Marcy B. Bolster, MD

Bisphosphonates, especially intravenous zoledronic acid, often cause influenza-like symptoms such as severe musculoskeletal pain, fever, headache, malaise, and fatigue, sometimes accompanied by nausea, vomiting, and diarrhea. As many as 30% of patients experience these symptoms, which are usually transient, last up to 1 week, and, in most patients, only rarely recur with subsequent infusions.

It is essential to counsel and reassure patients about these reactions before starting treatment. We recommend that patients take acetaminophen before intravenous bis­phosphonate infusions, and if an acute-phase reaction occurs, we provide adequate supportive care with acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs). If patients report severe musculoskeletal pain, then consider discontinuing the bisphosphonate treatment.

INFLUENZA-LIKE SYMPTOMS

The acute-phase reaction is a transient inflammatory state characterized by influenza-like symptoms such as fever, myalgia, joint pain, and nausea. It often occurs within the first few days after initial exposure to a bisphosphonate. Patients tend to rate the symptoms as mild to moderate. Symptoms may recur with subsequent doses; however, the incidence rate decreases substantially with each subsequent dose.

With intravenous bisphosphonates

Reid et al1 analyzed data from a trial in which 7,765 postmenopausal women with osteoporosis were randomized to receive intravenous zoledronic acid or placebo; 42.4% of the zoledronic acid group experienced symptoms that could be attributed to an acute-phase reaction after the first infusion, compared with 11.7% of the placebo group (P < .0001). Statistically significant differences (P < .0001) in symptoms between the groups included the following:

• Fever 20.3% vs 2.5%
• Musculoskeletal symptoms 19.9% vs 4.7% 
• Gastrointestinal symptoms 7.8% vs 2.1%.

Of the patients describing musculoskeletal symptoms after receiving zoledronic acid, most (79%) described them as generalized pain or discomfort, while about 25% said they were regional, usually localized to the back, neck, chest, and shoulders, 5% described joint stiffness, and 2.5% reported joint swelling.¹

In this and other studies,^1–3 acute-phase reactions most commonly occurred within the first few days after the infusion and were rated as mild to moderate in 90% of cases.^1,2 Patients who reported an acute-phase reaction were not more likely to opt out of subsequent infusions. The authors postulated that this was most likely because acute-phase reactions were mild and transient, and most resolved within 1 week.¹ The incidence decreased with each subsequent infusion of zoledronic acid^1–3; rates of the acute-phase reaction at years 1, 2, and 3 were 30%, 7%, and 3%, respectively.¹

With oral bisphosphonates

The acute-phase reaction is less common with oral bisphosphonates (occurring in 5.6% of patients in a retrospective study4) and is usually less severe.^4,5

Musculoskeletal pain related to the acute-phase reaction is thought to be due to transient release of inflammatory cytokines such as interleukin 6, interferon gamma, and tumor necrosis factor alpha from macrophages, monocytes, and gamma-delta T cells.⁶

Bisphosphonates are taken up by osteoclasts and inhibit their function. But bisphosphonates are not all the same: they can be divided into aminobisphosphonates (eg, alendronate, pamidronate, risedronate, zoledronic acid) and nonaminobisphosphonates (eg, clodronate, etidronate).

Inside the osteoclasts, aminobisphosphonates inhibit farnesyl diphosphate synthase in the meval­onate pathways, thus disrupting cell signaling and leading to apoptosis.⁷ However, inhibition of farnesyl diphosphate synthase also increases intracellular levels of isopentyl pyrophosphate, which induces T-cell activation; this is thought to result in release of inflammatory cytokines, leading to the acute-phase reaction.^7,8

In contrast, nonaminobisphosphonates such as clodronate and etidronate, after being internalized, are metabolized into nonhydrolyzable adenosine triphosphate, which is toxic to the osteoclast. The acute-phase reaction or influenza-like illness is unique to aminobisphosphonates; nonaminobisphosphonates have not been associated with an acute-phase reaction.

TRIALS OF PREVENTIVE TREATMENT

With NSAIDs, acetaminophen

Wark et al⁹ randomized 481 postmenopausal women who had osteopenia but who had never received bisphosphonates to 4 treatment groups:

• Zoledronic acid 5 mg intravenously plus acetaminophen 1,000 mg every 6 hours for 3 days
• Zoledronic acid 5 mg intravenously plus ibuprofen 400 mg every 6 hours for 3 days
• Zoledronic acid 5 mg intravenously plus 2 placebo capsules every 6 hours for 3 days
• Placebo infusion plus 2 placebo capsules every 6 hours for 3 days.

Patients were assessed for fever and worsening symptoms over 3 days after the infusion. The group that got zoledronic acid infusion and placebo capsules had the highest rates of fever (64%) and worsening symptoms (76%); acetaminophen and ibuprofen reduced these rates to an approximately equal extent, to 37% for fever and 46% (acetaminophen) and 49% (ibuprofen) for worsening symptoms. The group that received placebo bisphosphonate infusions had the lowest rates of fever (11%) and worsening symptoms (17%).

Silverman et al¹⁰ found that acetaminophen 650 mg taken 45 minutes before intravenous zoledronic acid infusion and continued every 6 hours for 3 days led to an absolute risk reduction of 21% in the incidence of fever or use of rescue medication compared with placebo.

Trials of other agents

In a study of 60 women,¹¹ 30 received an oral bolus of cholecalciferol 300,000 IU 5 days before zoledronic acid 5 mg infusion plus daily calcium 1,000 mg and vitamin D 800 IU, and 30 received a placebo pill 5 days before the same infusion and vitamin regimen as the other group. The preinfusion oral bolus did not decrease the incidence of acute-phase reactions, although it led to a small decrease in the severity of musculoskeletal pain (the median pain score was reduced from 2 to 1 on a scale of 0 to 10).

Other interventions such as fluvastatin and oral dexamethasone given before intravenous zoledronic acid did not reduce the severity or incidence of the acute-phase reaction.^10,12,13

Before starting bisphosphonate therapy, patients should be counseled about the possibility of acute musculoskeletal pain and other symptoms of the acute-phase reaction.

For intravenous bisphosphonates

We advise all patients scheduled to receive intravenous bisphosphonates to take acetaminophen 650 to 1,000 mg once on the morning of the infusion. We prefer acetaminophen over NSAIDs for prophylaxis to avoid the gastric mucosal and renal toxicity more common with NSAIDs, especially in the elderly.

If the patient has a history of acute musculoskeletal pain or other symptoms of an acute-phase reaction after bisphosphonate infusion, we advise a more aggressive approach to prophylaxis: acetaminophen 650 mg 1 hour before the infusion, then every 6 hours for up to 3 days. This approach, with acetaminophen or NSAIDs, has been shown in large randomized controlled trials to reduce the incidence and severity of the acute-phase reaction.

If an acute-phase reaction occurs, we inform patients that the likelihood decreases and is quite low with subsequent doses. We provide correct and honest information, so that patients who experience an acute-phase reaction can make an informed decision about continuing bisphosphonate treatment or switching to another treatment. If the patient decides to continue with intravenous bisphosphonate treatment, we recommend more-aggressive prophylaxis with acetaminophen or NSAIDs with subsequent infusions.

For oral bisphosphonates

We do not prescribe prophylactic treatment with acetaminophen or NSAIDs with oral bisphosphonates, but we do advise patients to take acetaminophen or NSAIDs as needed for mild to moderate musculoskeletal pain, should this occur.

We try to continue treatment in mild to moderate cases, while monitoring the patient closely to see if the musculoskeletal pain resolves within 1 to 2 weeks.

If the pain is severe or does not resolve in 1 to 2 weeks, we offer switching to another drug class. Since musculoskeletal pain with oral bisphosphonates does not represent an allergic reaction, we have switched patients from oral to intravenous bisphosphonates without recurrence of musculoskeletal pain.

SEVERE MUSCULOSKELETAL PAIN BEYOND THE ACUTE PHASE

Severe musculoskeletal pain that may not be related to the acute-phase reaction, although rare, has been reported.^5,14 From 1995, when alendronate was approved for osteoporosis, through 2002, the US Food and Drug Administration received reports of severe musculoskeletal pain in 117 patients.¹⁵

This severe musculoskeletal pain related to bisphosphonate use remains poorly characterized. It has been reported to occur days or months (median time 14 days, range same day to 52 months) after starting bisphosphonate therapy and to resolve only if the bisphosphonate is stopped.^5,15 It differs from typical acute-phase reactions, which tend to occur with the initial dose (intravenous or oral) and resolve within several days. There are case reports of polyarthritis with synovitis that recurred with each bisphosphonate dose (oral or intravenous) and led to discontinuation of the bisphosphonate.^14,16–18

Clinicians need to be aware of the possibility of severe musculoskeletal pain and consider stopping bisphosphonate treatment in these cases. Besides discontinuation, acetaminophen, NSAIDs, and, in rare cases, glucocorticoids or short-term opiate therapy may be used for symptom control. In patients with a severe or persistent acute-phase reaction or musculoskeletal pain, discontinuation of bisphosphonates is warranted.

Bisphosphonates, especially intravenous zoledronic acid, often cause influenza-like symptoms such as severe musculoskeletal pain, fever, headache, malaise, and fatigue, sometimes accompanied by nausea, vomiting, and diarrhea. As many as 30% of patients experience these symptoms, which are usually transient, last up to 1 week, and, in most patients, only rarely recur with subsequent infusions.

It is essential to counsel and reassure patients about these reactions before starting treatment. We recommend that patients take acetaminophen before intravenous bis­phosphonate infusions, and if an acute-phase reaction occurs, we provide adequate supportive care with acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs). If patients report severe musculoskeletal pain, then consider discontinuing the bisphosphonate treatment.

INFLUENZA-LIKE SYMPTOMS

The acute-phase reaction is a transient inflammatory state characterized by influenza-like symptoms such as fever, myalgia, joint pain, and nausea. It often occurs within the first few days after initial exposure to a bisphosphonate. Patients tend to rate the symptoms as mild to moderate. Symptoms may recur with subsequent doses; however, the incidence rate decreases substantially with each subsequent dose.

With intravenous bisphosphonates

Reid et al1 analyzed data from a trial in which 7,765 postmenopausal women with osteoporosis were randomized to receive intravenous zoledronic acid or placebo; 42.4% of the zoledronic acid group experienced symptoms that could be attributed to an acute-phase reaction after the first infusion, compared with 11.7% of the placebo group (P < .0001). Statistically significant differences (P < .0001) in symptoms between the groups included the following:

• Fever 20.3% vs 2.5%
• Musculoskeletal symptoms 19.9% vs 4.7% 
• Gastrointestinal symptoms 7.8% vs 2.1%.

Of the patients describing musculoskeletal symptoms after receiving zoledronic acid, most (79%) described them as generalized pain or discomfort, while about 25% said they were regional, usually localized to the back, neck, chest, and shoulders, 5% described joint stiffness, and 2.5% reported joint swelling.¹

In this and other studies,^1–3 acute-phase reactions most commonly occurred within the first few days after the infusion and were rated as mild to moderate in 90% of cases.^1,2 Patients who reported an acute-phase reaction were not more likely to opt out of subsequent infusions. The authors postulated that this was most likely because acute-phase reactions were mild and transient, and most resolved within 1 week.¹ The incidence decreased with each subsequent infusion of zoledronic acid^1–3; rates of the acute-phase reaction at years 1, 2, and 3 were 30%, 7%, and 3%, respectively.¹

With oral bisphosphonates

The acute-phase reaction is less common with oral bisphosphonates (occurring in 5.6% of patients in a retrospective study4) and is usually less severe.^4,5

Musculoskeletal pain related to the acute-phase reaction is thought to be due to transient release of inflammatory cytokines such as interleukin 6, interferon gamma, and tumor necrosis factor alpha from macrophages, monocytes, and gamma-delta T cells.⁶

Bisphosphonates are taken up by osteoclasts and inhibit their function. But bisphosphonates are not all the same: they can be divided into aminobisphosphonates (eg, alendronate, pamidronate, risedronate, zoledronic acid) and nonaminobisphosphonates (eg, clodronate, etidronate).

Inside the osteoclasts, aminobisphosphonates inhibit farnesyl diphosphate synthase in the meval­onate pathways, thus disrupting cell signaling and leading to apoptosis.⁷ However, inhibition of farnesyl diphosphate synthase also increases intracellular levels of isopentyl pyrophosphate, which induces T-cell activation; this is thought to result in release of inflammatory cytokines, leading to the acute-phase reaction.^7,8

In contrast, nonaminobisphosphonates such as clodronate and etidronate, after being internalized, are metabolized into nonhydrolyzable adenosine triphosphate, which is toxic to the osteoclast. The acute-phase reaction or influenza-like illness is unique to aminobisphosphonates; nonaminobisphosphonates have not been associated with an acute-phase reaction.

TRIALS OF PREVENTIVE TREATMENT

With NSAIDs, acetaminophen

Wark et al⁹ randomized 481 postmenopausal women who had osteopenia but who had never received bisphosphonates to 4 treatment groups:

• Zoledronic acid 5 mg intravenously plus acetaminophen 1,000 mg every 6 hours for 3 days
• Zoledronic acid 5 mg intravenously plus ibuprofen 400 mg every 6 hours for 3 days
• Zoledronic acid 5 mg intravenously plus 2 placebo capsules every 6 hours for 3 days
• Placebo infusion plus 2 placebo capsules every 6 hours for 3 days.

Patients were assessed for fever and worsening symptoms over 3 days after the infusion. The group that got zoledronic acid infusion and placebo capsules had the highest rates of fever (64%) and worsening symptoms (76%); acetaminophen and ibuprofen reduced these rates to an approximately equal extent, to 37% for fever and 46% (acetaminophen) and 49% (ibuprofen) for worsening symptoms. The group that received placebo bisphosphonate infusions had the lowest rates of fever (11%) and worsening symptoms (17%).

Silverman et al¹⁰ found that acetaminophen 650 mg taken 45 minutes before intravenous zoledronic acid infusion and continued every 6 hours for 3 days led to an absolute risk reduction of 21% in the incidence of fever or use of rescue medication compared with placebo.

Trials of other agents

In a study of 60 women,¹¹ 30 received an oral bolus of cholecalciferol 300,000 IU 5 days before zoledronic acid 5 mg infusion plus daily calcium 1,000 mg and vitamin D 800 IU, and 30 received a placebo pill 5 days before the same infusion and vitamin regimen as the other group. The preinfusion oral bolus did not decrease the incidence of acute-phase reactions, although it led to a small decrease in the severity of musculoskeletal pain (the median pain score was reduced from 2 to 1 on a scale of 0 to 10).

Other interventions such as fluvastatin and oral dexamethasone given before intravenous zoledronic acid did not reduce the severity or incidence of the acute-phase reaction.^10,12,13

Before starting bisphosphonate therapy, patients should be counseled about the possibility of acute musculoskeletal pain and other symptoms of the acute-phase reaction.

For intravenous bisphosphonates

We advise all patients scheduled to receive intravenous bisphosphonates to take acetaminophen 650 to 1,000 mg once on the morning of the infusion. We prefer acetaminophen over NSAIDs for prophylaxis to avoid the gastric mucosal and renal toxicity more common with NSAIDs, especially in the elderly.

If the patient has a history of acute musculoskeletal pain or other symptoms of an acute-phase reaction after bisphosphonate infusion, we advise a more aggressive approach to prophylaxis: acetaminophen 650 mg 1 hour before the infusion, then every 6 hours for up to 3 days. This approach, with acetaminophen or NSAIDs, has been shown in large randomized controlled trials to reduce the incidence and severity of the acute-phase reaction.

If an acute-phase reaction occurs, we inform patients that the likelihood decreases and is quite low with subsequent doses. We provide correct and honest information, so that patients who experience an acute-phase reaction can make an informed decision about continuing bisphosphonate treatment or switching to another treatment. If the patient decides to continue with intravenous bisphosphonate treatment, we recommend more-aggressive prophylaxis with acetaminophen or NSAIDs with subsequent infusions.

For oral bisphosphonates

We do not prescribe prophylactic treatment with acetaminophen or NSAIDs with oral bisphosphonates, but we do advise patients to take acetaminophen or NSAIDs as needed for mild to moderate musculoskeletal pain, should this occur.

We try to continue treatment in mild to moderate cases, while monitoring the patient closely to see if the musculoskeletal pain resolves within 1 to 2 weeks.

If the pain is severe or does not resolve in 1 to 2 weeks, we offer switching to another drug class. Since musculoskeletal pain with oral bisphosphonates does not represent an allergic reaction, we have switched patients from oral to intravenous bisphosphonates without recurrence of musculoskeletal pain.

SEVERE MUSCULOSKELETAL PAIN BEYOND THE ACUTE PHASE

Severe musculoskeletal pain that may not be related to the acute-phase reaction, although rare, has been reported.^5,14 From 1995, when alendronate was approved for osteoporosis, through 2002, the US Food and Drug Administration received reports of severe musculoskeletal pain in 117 patients.¹⁵

This severe musculoskeletal pain related to bisphosphonate use remains poorly characterized. It has been reported to occur days or months (median time 14 days, range same day to 52 months) after starting bisphosphonate therapy and to resolve only if the bisphosphonate is stopped.^5,15 It differs from typical acute-phase reactions, which tend to occur with the initial dose (intravenous or oral) and resolve within several days. There are case reports of polyarthritis with synovitis that recurred with each bisphosphonate dose (oral or intravenous) and led to discontinuation of the bisphosphonate.^14,16–18

Clinicians need to be aware of the possibility of severe musculoskeletal pain and consider stopping bisphosphonate treatment in these cases. Besides discontinuation, acetaminophen, NSAIDs, and, in rare cases, glucocorticoids or short-term opiate therapy may be used for symptom control. In patients with a severe or persistent acute-phase reaction or musculoskeletal pain, discontinuation of bisphosphonates is warranted.

Bisphosphonates, especially intravenous zoledronic acid, often cause influenza-like symptoms such as severe musculoskeletal pain, fever, headache, malaise, and fatigue, sometimes accompanied by nausea, vomiting, and diarrhea. As many as 30% of patients experience these symptoms, which are usually transient, last up to 1 week, and, in most patients, only rarely recur with subsequent infusions.

It is essential to counsel and reassure patients about these reactions before starting treatment. We recommend that patients take acetaminophen before intravenous bis­phosphonate infusions, and if an acute-phase reaction occurs, we provide adequate supportive care with acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs). If patients report severe musculoskeletal pain, then consider discontinuing the bisphosphonate treatment.

INFLUENZA-LIKE SYMPTOMS

The acute-phase reaction is a transient inflammatory state characterized by influenza-like symptoms such as fever, myalgia, joint pain, and nausea. It often occurs within the first few days after initial exposure to a bisphosphonate. Patients tend to rate the symptoms as mild to moderate. Symptoms may recur with subsequent doses; however, the incidence rate decreases substantially with each subsequent dose.

With intravenous bisphosphonates

Reid et al1 analyzed data from a trial in which 7,765 postmenopausal women with osteoporosis were randomized to receive intravenous zoledronic acid or placebo; 42.4% of the zoledronic acid group experienced symptoms that could be attributed to an acute-phase reaction after the first infusion, compared with 11.7% of the placebo group (P < .0001). Statistically significant differences (P < .0001) in symptoms between the groups included the following:

• Fever 20.3% vs 2.5%
• Musculoskeletal symptoms 19.9% vs 4.7% 
• Gastrointestinal symptoms 7.8% vs 2.1%.

Of the patients describing musculoskeletal symptoms after receiving zoledronic acid, most (79%) described them as generalized pain or discomfort, while about 25% said they were regional, usually localized to the back, neck, chest, and shoulders, 5% described joint stiffness, and 2.5% reported joint swelling.¹

In this and other studies,^1–3 acute-phase reactions most commonly occurred within the first few days after the infusion and were rated as mild to moderate in 90% of cases.^1,2 Patients who reported an acute-phase reaction were not more likely to opt out of subsequent infusions. The authors postulated that this was most likely because acute-phase reactions were mild and transient, and most resolved within 1 week.¹ The incidence decreased with each subsequent infusion of zoledronic acid^1–3; rates of the acute-phase reaction at years 1, 2, and 3 were 30%, 7%, and 3%, respectively.¹

With oral bisphosphonates

The acute-phase reaction is less common with oral bisphosphonates (occurring in 5.6% of patients in a retrospective study4) and is usually less severe.^4,5

Musculoskeletal pain related to the acute-phase reaction is thought to be due to transient release of inflammatory cytokines such as interleukin 6, interferon gamma, and tumor necrosis factor alpha from macrophages, monocytes, and gamma-delta T cells.⁶

Bisphosphonates are taken up by osteoclasts and inhibit their function. But bisphosphonates are not all the same: they can be divided into aminobisphosphonates (eg, alendronate, pamidronate, risedronate, zoledronic acid) and nonaminobisphosphonates (eg, clodronate, etidronate).

Inside the osteoclasts, aminobisphosphonates inhibit farnesyl diphosphate synthase in the meval­onate pathways, thus disrupting cell signaling and leading to apoptosis.⁷ However, inhibition of farnesyl diphosphate synthase also increases intracellular levels of isopentyl pyrophosphate, which induces T-cell activation; this is thought to result in release of inflammatory cytokines, leading to the acute-phase reaction.^7,8

In contrast, nonaminobisphosphonates such as clodronate and etidronate, after being internalized, are metabolized into nonhydrolyzable adenosine triphosphate, which is toxic to the osteoclast. The acute-phase reaction or influenza-like illness is unique to aminobisphosphonates; nonaminobisphosphonates have not been associated with an acute-phase reaction.

TRIALS OF PREVENTIVE TREATMENT

With NSAIDs, acetaminophen

Wark et al⁹ randomized 481 postmenopausal women who had osteopenia but who had never received bisphosphonates to 4 treatment groups:

• Zoledronic acid 5 mg intravenously plus acetaminophen 1,000 mg every 6 hours for 3 days
• Zoledronic acid 5 mg intravenously plus ibuprofen 400 mg every 6 hours for 3 days
• Zoledronic acid 5 mg intravenously plus 2 placebo capsules every 6 hours for 3 days
• Placebo infusion plus 2 placebo capsules every 6 hours for 3 days.

Patients were assessed for fever and worsening symptoms over 3 days after the infusion. The group that got zoledronic acid infusion and placebo capsules had the highest rates of fever (64%) and worsening symptoms (76%); acetaminophen and ibuprofen reduced these rates to an approximately equal extent, to 37% for fever and 46% (acetaminophen) and 49% (ibuprofen) for worsening symptoms. The group that received placebo bisphosphonate infusions had the lowest rates of fever (11%) and worsening symptoms (17%).

Silverman et al¹⁰ found that acetaminophen 650 mg taken 45 minutes before intravenous zoledronic acid infusion and continued every 6 hours for 3 days led to an absolute risk reduction of 21% in the incidence of fever or use of rescue medication compared with placebo.

Trials of other agents

In a study of 60 women,¹¹ 30 received an oral bolus of cholecalciferol 300,000 IU 5 days before zoledronic acid 5 mg infusion plus daily calcium 1,000 mg and vitamin D 800 IU, and 30 received a placebo pill 5 days before the same infusion and vitamin regimen as the other group. The preinfusion oral bolus did not decrease the incidence of acute-phase reactions, although it led to a small decrease in the severity of musculoskeletal pain (the median pain score was reduced from 2 to 1 on a scale of 0 to 10).

Other interventions such as fluvastatin and oral dexamethasone given before intravenous zoledronic acid did not reduce the severity or incidence of the acute-phase reaction.^10,12,13

Before starting bisphosphonate therapy, patients should be counseled about the possibility of acute musculoskeletal pain and other symptoms of the acute-phase reaction.

For intravenous bisphosphonates

We advise all patients scheduled to receive intravenous bisphosphonates to take acetaminophen 650 to 1,000 mg once on the morning of the infusion. We prefer acetaminophen over NSAIDs for prophylaxis to avoid the gastric mucosal and renal toxicity more common with NSAIDs, especially in the elderly.

If the patient has a history of acute musculoskeletal pain or other symptoms of an acute-phase reaction after bisphosphonate infusion, we advise a more aggressive approach to prophylaxis: acetaminophen 650 mg 1 hour before the infusion, then every 6 hours for up to 3 days. This approach, with acetaminophen or NSAIDs, has been shown in large randomized controlled trials to reduce the incidence and severity of the acute-phase reaction.

If an acute-phase reaction occurs, we inform patients that the likelihood decreases and is quite low with subsequent doses. We provide correct and honest information, so that patients who experience an acute-phase reaction can make an informed decision about continuing bisphosphonate treatment or switching to another treatment. If the patient decides to continue with intravenous bisphosphonate treatment, we recommend more-aggressive prophylaxis with acetaminophen or NSAIDs with subsequent infusions.

For oral bisphosphonates

We do not prescribe prophylactic treatment with acetaminophen or NSAIDs with oral bisphosphonates, but we do advise patients to take acetaminophen or NSAIDs as needed for mild to moderate musculoskeletal pain, should this occur.

We try to continue treatment in mild to moderate cases, while monitoring the patient closely to see if the musculoskeletal pain resolves within 1 to 2 weeks.

If the pain is severe or does not resolve in 1 to 2 weeks, we offer switching to another drug class. Since musculoskeletal pain with oral bisphosphonates does not represent an allergic reaction, we have switched patients from oral to intravenous bisphosphonates without recurrence of musculoskeletal pain.

SEVERE MUSCULOSKELETAL PAIN BEYOND THE ACUTE PHASE

Severe musculoskeletal pain that may not be related to the acute-phase reaction, although rare, has been reported.^5,14 From 1995, when alendronate was approved for osteoporosis, through 2002, the US Food and Drug Administration received reports of severe musculoskeletal pain in 117 patients.¹⁵

This severe musculoskeletal pain related to bisphosphonate use remains poorly characterized. It has been reported to occur days or months (median time 14 days, range same day to 52 months) after starting bisphosphonate therapy and to resolve only if the bisphosphonate is stopped.^5,15 It differs from typical acute-phase reactions, which tend to occur with the initial dose (intravenous or oral) and resolve within several days. There are case reports of polyarthritis with synovitis that recurred with each bisphosphonate dose (oral or intravenous) and led to discontinuation of the bisphosphonate.^14,16–18

Clinicians need to be aware of the possibility of severe musculoskeletal pain and consider stopping bisphosphonate treatment in these cases. Besides discontinuation, acetaminophen, NSAIDs, and, in rare cases, glucocorticoids or short-term opiate therapy may be used for symptom control. In patients with a severe or persistent acute-phase reaction or musculoskeletal pain, discontinuation of bisphosphonates is warranted.

Drug-induced osteoporosis is common, and the list of drugs that can harm bone continues to grow. As part of routine health maintenance, practitioners should recognize the drugs that increase bone loss and take measures to mitigate these effects to help avoid osteopenia and osteoporosis.

Osteoporosis, a silent systemic disease defined by low bone mineral density and changes in skeletal microstructure, leads to a higher risk of fragility fractures. Some of the risk factors are well described, but less well known is the role of pharmacologic therapy. The implicated drugs (Table 1) have important therapeutic roles, so the benefits of using them must be weighed against their risks, including their potential effects on bone.

This review focuses on a few drugs known to increase fracture risk, their mechanisms of bone loss, and management considerations (Table 2).

GLUCOCORTICOIDS

Glucocorticoids are used to treat many medical conditions, including allergic, rheumatic, and other inflammatory diseases, and as immunosuppressive therapy after solid organ and bone marrow transplant. They are the most common cause of drug-induced bone loss and related secondary osteoporosis.

Multiple effects on bone

Glucocorticoids both increase bone resorption and decrease bone formation by a variety of mechanisms.¹ They reduce intestinal calcium absorption, increase urinary excretion of calcium, and enhance osteocyte apoptosis, leading to deterioration of the bone microarchitecture and bone mineral density.² They also affect sex hormones, decreasing testosterone production in men and estrogen in women, leading to increased bone resorption, altered bone architecture, and poorer bone quality.^3,4 The bone loss is greater in trabecular bone (eg, the femoral neck and vertebral bodies) than in cortical bone (eg, the forearm).⁵

Glucocorticoids have other systemic effects that increase fracture risk. For example, they cause muscle weakness and atrophy, increasing the risk of falls.⁴ Additionally, many of the inflammatory conditions for which they are prescribed (eg, rheumatoid arthritis) also increase the risk of osteoporosis by means of proinflammatory cytokine production, which may contribute to systemic and local effects on bone.^4,6

Bone mineral density declines quickly

Bone mineral density declines within the first 3 months after starting oral glucocorticoids, with the rate of bone loss peaking at 6 months. Up to 12% of bone mass is lost in the first year. In subsequent years of continued use, bone loss progresses at a slower, steadier rate, averaging 2% to 3% annually.^5,7,8

Oral therapy increases fracture risk

Kanis et al⁹ performed a meta-analysis of seven prospective cohort studies in 40,000 patients and found that the current or previous use of an oral glucocorticoid increased the risk of fragility fractures, and that men and women were  affected about equally.⁹

Van Staa et al^10,11 reported that daily doses of glucocorticoids equivalent to more than 2.5 mg of prednisone were associated with an increased risk of vertebral and hip fractures; fracture risk was related mainly to daily dosage rather than cumulative dose.

Van Staa et al,¹² in a retrospective cohort study, compared nearly 250,000 adult users of oral glucocorticoids from general medical practice settings with the same number of controls matched for sex, age, and medical practice. The relative risks for fractures and 95% confidence intervals (CIs) during oral glucocorticoid treatment were as follows:

• Forearm fracture 1.09 (1.01–1.17)
• Nonvertebral fracture 1.33 (1.29–1.38)
• Hip fracture 1.61 (1.47–1.76)
• Vertebral fracture 2.60 (2.31–2.92).

The risk was dose-dependent. For a low daily dose (< 2.5 mg/day of prednisolone), the relative risks were:

• Hip fracture 0.99 (0.82–1.20)
• Vertebral fracture 1.55 (1.20–2.01) .

For a medium daily dose (2.5–7.5 mg/day), the relative risks were: 

• Hip fracture 1.77 (1.55–2.02)
• Vertebral fracture 2.59 (2.16–3.10) .

For a high daily dose (> 7.5 mg/day), the relative risks were:

• Hip fracture 2.27 (1.94–2.66)
• Vertebral fracture 5.18 (4.25–6.31).

Fracture risk rapidly declined toward baseline after the patients stopped taking oral glucocorticoids but did not return to baseline levels. The lessening of excess fracture risk occurred mainly within the first year after stopping therapy.

Other studies^5,9,13 have suggested that the increased fracture risk is mostly independent of bone mineral density, and that other mechanisms are at play. One study¹⁴ found that oral glucocorticoid users with a prevalent vertebral fracture actually had higher bone mineral density than patients with a fracture not taking glucocorticoids, although this finding was not confirmed in a subsequent study.¹⁵

Inhaled glucocorticoids have less effect on bone

Inhaled glucocorticoids are commonly used to treat chronic obstructive pulmonary disease and asthma. They do not have the same systemic bioavailability as oral glucocorticoids, so the risk of adverse effects is lower.

Data are inconsistent among several studies that evaluated the relationship between inhaled glucocorticoids, bone mineral density, osteoporosis, and fragility fracture. The inconsistencies may be due to heterogeneity of the study populations, self-reporting of fractures, and different methods of assessing chronic obstructive pulmonary disease severity.¹⁶

A Cochrane review¹⁷ in 2002 evaluated seven randomized controlled trials that compared the use of inhaled glucocorticoids vs placebo in nearly 2,000 patients with mild asthma or chronic obstructive pulmonary disease and found no evidence for decreased bone mineral density, increased bone turnover, or increased vertebral fracture incidence in the glucocorticoid users at 2 to 3 years of follow-up (odds ratio for fracture 1.87, 95% CI 0.5–7.0).

The Evaluation of Obstructive Lung Disease and Osteoporosis study,¹⁶ a multicenter Italian observational epidemiologic study, reported that patients taking the highest daily doses of inhaled glucocorticoids (> 1,500 μg of beclomethasone or its equivalent) had a significantly higher risk of vertebral fracture (odds ratio 1.4, 95% CI 1.04–1.89).¹⁶

A meta-analysis¹⁸ of five case-control studies (43,783 cases and 259,936 controls) identified a possible dose-dependent relationship, with a relative risk for nonvertebral fracture of 1.12 (95% CI 1.0–1.26) for each 1,000-μg increase in beclomethasone-equivalent inhaled glucocorticoid per day.

In summary, the effects of inhaled glucocorticoids in adults are uncertain, although trends toward increased fracture risk and decreased bone mineral density are evident with chronic therapy at moderate to high dosages. The risks and benefits of treatment should be carefully considered in patients with osteoporosis and baseline elevated fracture risk.¹⁹

Managing the risk of glucocorticoid-induced osteoporosis

In 2010, the American College of Rheumatology published recommendations for preventing and treating glucocorticoid-induced osteoporosis, which were endorsed by the American Society for Bone and Mineral Research.²⁰ To lessen the risk of osteoporosis, the recommendations are as follows:

Limit exposure. Patients receiving glucocorticoids should be given the smallest dosage for the shortest duration possible.

Advise lifestyle changes. Patients should be counseled to limit their alcohol intake to no more than two drinks per day, to quit smoking, to engage in weight-bearing exercise, and to ingest enough calcium (1,200–1,500 mg/day, through diet and supplements) and vitamin D.

Monitor bone mineral density. Patients starting glucocorticoids at any dosage for an expected duration of at least 3 months should have their bone mineral density measured at baseline. The frequency of subsequent measurements should be based on the presence of other risk factors for fracture, results of previous bone density testing, glucocorticoid dosage, whether therapy for bone health has been initiated, and the rate of change in bone mineral density. If warranted and if the results would lead to a change in management, patients can undergo dual-energy x-ray absorptiometry more often than usual, ie, more often than every 2 years. Prevalent and incident fragility fractures, height measurements, fall risk assessments, laboratory measurements of 25-hydroxyvitamin D, and consideration of vertebral fracture assessment or other imaging of the spine, as necessary, should be part of counseling and monitoring.

Osteoporosis treatment. For patients who will be taking glucocorticoids for at least 3 months, alendronate, risedronate, zoledronic acid, or teriparatide can be initiated to prevent or treat osteoporosis in the following groups: 

• Postmenopausal women and men over age 50 if the daily glucocorticoid dosage is at least 7.5 mg/day or if the World Health Organization Fracture Risk Assessment Tool (FRAX) score is more than 10% (the threshold for medium fracture risk)
• Premenopausal women and men younger than 50 if they have a history of fragility fracture, the FRAX score is more than 20% (the threshold for high fracture risk), or the T score is less than –2.5.

Certain clinical factors can also put a patient into a higher-risk category. These include current tobacco use, low body mass index, parental history of hip fracture, consuming more than three alcoholic drinks daily, higher daily or cumulative glucocorticoid dosage, intravenous pulse glucocorticoid usage, or a decline in central bone mineral density that exceeds the least significant change according to the scanner used.²⁰

The FRAX tool accounts for bone density only at the femoral neck, and while useful, it cannot replace clinical judgment in stratifying risk. Moreover, it does not apply to premenopausal women or men under age 40.

The implicated medications have important roles, so weigh their risks and benefits

The long-term risks of medications to treat glucocorticoid-induced osteoporosis are not well defined for premenopausal women (or their unborn children) or in men younger than 40, so treatment is recommended in those groups only for those with prevalent fragility fractures who are clearly at higher risk of additional fractures.²⁰

PROTON PUMP INHIBITORS

Proton pump inhibitors are available by prescription and over the counter for gastric acid-related conditions. Concerns have been raised that these highly effective drugs are overused.²¹ Several of their adverse effects are self-limited and minor, but long-term use may entail serious risks, including propensity to bone fracture.²²

Low acid leads to poor calcium absorption

Why fracture risk increases with proton pump inhibitors is controversial and may relate to their desired effect of suppressing gastric acid production: calcium salts, including carbonate and chloride, are poorly soluble and require an acidic environment to increase calcium ionization and thus absorption.²³ For this reason, if patients taking a proton pump inhibitor take a calcium supplement, it should be calcium citrate, which unlike calcium carbonate does not require an acid environment for absorption.

Higher risk in older patients, with longer use, and with higher dosage

Since the first reports on proton pump inhibitors and fracture risk were published in 2006,^24,25 a number of studies have reported this association, including several systematic reviews.

In 2011, the US Food and Drug Administration (FDA) updated a 2010 safety communication based on seven epidemiologic studies reporting an increased risk of fractures of the spine, hip, and wrist with proton pump inhibitors.^24–31 Time of exposure to a proton pump inhibitor in these studies varied from 1 to 12 years. Fracture risk was higher in older patients,²⁶ with higher doses,^24,29 and with longer duration of drug use.^24,27 On the other hand, one study that included only patients without other major fracture risk factors failed to find an association between the use of proton pump inhibitors and fractures.²⁸

Is evidence sufficient for changing use?

The FDA report included a disclaimer that they had no access to study data or protocols and so could not verify the findings.²⁶ Moreover, the studies used claims data from computerized databases to evaluate the risk of fractures in patients treated with proton pump inhibitors compared with those not using these drugs.^24–31 Information was often incomplete regarding potentially important factors (eg, falls, family history of osteoporosis, calcium and vitamin D intake, smoking, alcohol use, reason for medication use), as well as the timing of drug use related to the onset or worsening of osteoporosis.²⁶

Although 34 published studies evaluated the association of fracture risk and proton pump inhibitors, Leontiadis and Moayyedi³² argued that insufficient evidence exists to change our prescribing habits for these drugs based on fracture risk, as the studies varied considerably in their designs and results, a clear dose-response relationship is lacking, and the modest association is likely related to multiple confounders.

Bottom line: Use with caution

Although the increased fracture risk associated with proton pump inhibitors is likely multifactorial and is not fully delineated, it appears to be real. These drugs should be used only if there is a clear indication for them and if their benefits likely outweigh their risks. The lowest effective dose should be used, and the need for continuing use should be frequently reassessed.

SELECTIVE SEROTONIN REUPTAKE INHIBITORS

Depression affects 1 in 10 people in the United States, is especially common in the elderly, and leads to significant morbidity and reduced quality of life.³³ Selective serotonin reuptake inhibitors (SSRIs) are often prescribed and are generally considered first-line agents for treating depression.

Complex bone effects

Use proton pump inhibitors only if there is a clear indication for them and their benefits likely outweigh the risks

SSRIs antagonize the serotonin transporter, which normally assists serotonin uptake from the extracellular space. The serotonin transporter is found in all main types of bone cells, including osteoclasts, osteoblasts, and osteocytes.³³ Serotonin is made by different genes in the brain than in the periphery, causing opposing effects on bone biology: when generated peripherally, it acts as a hormone to inhibit bone formation, while when generated in the brain, it acts as a neurotransmitter to create a major and positive effect on bone mass accrual by enhancing bone formation and limiting bone resorption.^34,35

Potential confounders complicate the effect of SSRIs on bone health, as depression itself may be a risk factor for fracture. Patients with depression tend to have increased inflammation and cortisol, decreased gonadal steroids, more behavioral risk factors such as tobacco and increased alcohol use, and less physical activity, all of which can contribute to low bone density and risk of falls and fractures.³³

Daily use of SSRIs increases fracture risk

A 2012 meta-analysis³⁶ of 12 studies (seven case-control and five cohort), showed that SSRI users had a higher overall risk of fracture (adjusted odds ratio 1.69, 95% CI 1.51–1.90). By anatomic site, pooled odds ratios and 95% CIs were:

• Vertebral fractures 1.34 (1.13–1.59)
• Wrist or forearm fractures 1.51 (1.26–1.82)
• Hip or femur fractures 2.06 (1.84–2.30). 

A 2013 meta-analysis³⁷ of 34 studies with more than 1 million patients found that the random-effects pooled relative risk of all fracture types in users of antidepressants (including but not limited to SSRIs) was 1.39 (95% CI 1.32–1.47) compared with nonusers. Relative risks and 95% CIs in antidepressant users were:

• Vertebral fractures 1.38 (1.19–1.61)
• Nonvertebral fractures 1.42 (1.34–1.51)
• Hip fractures 1.47 (1.36–1.58).

A population-based, prospective cohort study³⁸ of 5,008 community-dwelling adults age 50 and older, followed for 5 years, found that the daily use of SSRIs was associated with a twofold increased risk of clinical fragility fractures (defined as minimal trauma fractures that were clinically reported and radiographically confirmed) after adjusting for potential covariates. Daily SSRI use was also associated with an increased risk of falling (odds ratio 2.2, 95% CI 1.4–3.5), lower bone mineral density at the hip, and a trend toward lower bone mineral density at the spine. These effects were dose-dependent and were similar for those who reported taking SSRIs at baseline and at 5 years.

Bottom line: Counsel bone health

Although no guidelines exist for preventing or treating SSRI-induced bone loss, providers should discuss with patients the potential effect of these medications on bone health, taking into account patient age, severity of depression, sex, duration of use, length of SSRI treatment, and other clinical risk factors for osteoporosis.³⁴ Given the widespread use of these medications for treating depression, more study into this association is needed to further guide providers.

ANTIEPILEPTIC DRUGS

Antiepileptic drugs are used to treat not only seizure disorders but also migraine headaches, neuropathy, and psychiatric and pain disorders. Many studies have linked their use to an increased risk of fractures.

The mechanism of this effect remains controversial. Early studies reported that inducers of cytochrome P450 enzymes (eg, phenobarbital, phenytoin) lead to increased vitamin D degradation, causing osteomalacia.³⁹ Another study suggested that changes in calcium metabolism and reduced bone mineral density occur without vitamin D deficiency and that drugs such as valproate that do not induce cytochrome P450 enzymes may also affect bone health.⁴⁰ Other bone effects may include direct inhibition of intestinal calcium absorption (seen in animal studies) and the induction of a high remodeling state leading to osteomalacia.^41,42

Epilepsy itself increases risk of fractures

Patients with seizure disorders may also have an increased risk of fractures because of falls, trauma, impaired balance, use of glucocorticoids and benzodiazepines, and comorbid conditions (eg, mental retardation, cerebral palsy, and brain neoplasm).⁴³

A 2005 meta-analysis⁴³ of 11 studies of epilepsy and fracture risk and 12 studies of epilepsy and bone mineral density found that the risks of fractures were increased. The following relative risks and 95% CIs were noted:

The benefit of preventing seizures outweighs the risks of fractures

• Any fracture 2.2 (1.9–2.5), in five studies
• Forearm 1.7 (1.2–2.3), in six studies
• Hip 5.3 (3.2–8.8), six studies
• Spine 6.2 (2.5–15.5), in three studies.

A large proportion of fractures (35%) seemed related to seizures.

Certain drugs increase risk

A large 2004 population-based, case-control, study⁴⁴ (124,655 fracture cases and 373,962 controls) found an association between the use of antiepileptic drugs and increased fracture risk. After adjusting for current or prior use of glucocorticoids, prior fracture, social variables, comorbid conditions, and epilepsy diagnosis, excess fracture risk was found to be associated with the following drugs (odds ratios and 95% CIs):

• Oxcarbazepine 1.14 (1.03–1.26)
• Valproate 1.15 (1.05–1.26)
• Carbamazepine 1.18 (1.10-1.26)
• Phenobarbital 1.79 (1.64–1.95).

The risk was higher with higher doses. Fracture risk was higher with cytochrome P450 enzyme-inducing drugs (carbamazepine, oxcarbazepine, phenobarbital, phenytoin, and primidone; odds ratio 1.38, 95% CI 1.31–1.45) than for noninducing drugs (clonazepam, ethosuximide, lamotrigine, tiagabine, topiramate, valproate, and vigabatrin; odds ratio 1.19, 95% CI 1.11–1.27). No significant increased risk of fracture was found with use of phenytoin, tiagabine, topiramate, ethosuximide, lamotrigine, vigabatrin, or primidone after adjusting for confounders. 

Bottom line: Monitor bone health

With antiepileptic drugs, the benefit of preventing seizures outweighs the risks of fractures. Patients on long-term antiepileptic drug therapy should be monitored for bone mineral density and vitamin D levels and receive counseling on lifestyle measures including tobacco cessation, alcohol moderation, and fall prevention.⁴⁵ As there are no evidence-based guidelines for bone health in patients on antiepileptic drugs, management should be based on current guidelines for treating osteoporosis.

AROMATASE INHIBITORS

Depression itself may be a risk factor for fracture

Breast cancer is the most common cancer in women and is the second-leading cause of cancer-associated deaths in women after lung cancer. Aromatase inhibitors, such as anastrozole, letrozole, and exemestane, are the standard of care in adjuvant treatment for hormone-receptor-positive breast cancer, leading to longer disease-free survival.

However, aromatase inhibitors increase bone loss and fracture risk, and only partial recovery of bone mineral density occurs after treatment is stopped. The drugs deter the aromatization of androgens and their conversion to estrogens in peripheral tissue, leading to reduced estrogen levels and resulting bone loss.⁴⁶ Anastrozole and letrozole have been found to reduce bone mineral density, increase bone turnover, and increase the relative risk for nonvertebral and vertebral fractures in postmenopausal women by 40% compared with tamoxifen.^47,48

Base osteoporosis treatment on risk

Several groups have issued guidelines for preventing and treating bone loss in postmenopausal women being treated with an aromatase inhibitor. When initiating treatment, women should be counseled about modifiable risk factors, exercise, and calcium and vitamin D supplementation.

Baseline bone mineral testing should also be obtained when starting treatment. Hadji et al,⁴⁹ in a review article, recommend starting bone-directed therapy if the patient’s T score is less than –2.0 (using the lowest score from three sites) or if she has any of at least two of the following fracture risk factors:

• T score less than –1.5
• Age over 65
• Family history of hip fracture
• Personal history of fragility fracture after age 50
• Low body mass index (< 20 kg/m²)
• Current or prior history of tobacco use
• Oral glucocorticoid use for longer than 6 months.

Patients with a T score at or above –2.0 and no risk factors should have bone mineral density reassessed after 1 to 2 years. Antiresorptive therapy with intravenous zoledronic acid and evaluation for other secondary causes of bone loss should be initiated for either:

• An annual decrease of at least 10% or
• An annual decrease of at least 4% in patients with osteopenia at baseline.⁴⁹

In 2003, the American Society of Clinical Oncology updated its recommendations on the role of bisphosphonates and bone health in women with breast cancer.⁵⁰ They recommend the following:

• If the T score is –2.5 or less, prescribe a bisphosphonate (alendronate, risedronate, or zoledronic acid)
• If the T score is –1.0 to –2.5, tailor treatment individually and monitor bone mineral density annually
• If the T score is greater than –1.0, monitor bone mineral density annually.

All patients should receive lifestyle counseling, calcium and vitamin D supplementation, and monitoring of additional risk factors for osteoporosis as appropriate.⁵⁰

Drug-induced osteoporosis is common, and the list of drugs that can harm bone continues to grow. As part of routine health maintenance, practitioners should recognize the drugs that increase bone loss and take measures to mitigate these effects to help avoid osteopenia and osteoporosis.

Osteoporosis, a silent systemic disease defined by low bone mineral density and changes in skeletal microstructure, leads to a higher risk of fragility fractures. Some of the risk factors are well described, but less well known is the role of pharmacologic therapy. The implicated drugs (Table 1) have important therapeutic roles, so the benefits of using them must be weighed against their risks, including their potential effects on bone.

This review focuses on a few drugs known to increase fracture risk, their mechanisms of bone loss, and management considerations (Table 2).

GLUCOCORTICOIDS

Glucocorticoids are used to treat many medical conditions, including allergic, rheumatic, and other inflammatory diseases, and as immunosuppressive therapy after solid organ and bone marrow transplant. They are the most common cause of drug-induced bone loss and related secondary osteoporosis.

Multiple effects on bone

Glucocorticoids both increase bone resorption and decrease bone formation by a variety of mechanisms.¹ They reduce intestinal calcium absorption, increase urinary excretion of calcium, and enhance osteocyte apoptosis, leading to deterioration of the bone microarchitecture and bone mineral density.² They also affect sex hormones, decreasing testosterone production in men and estrogen in women, leading to increased bone resorption, altered bone architecture, and poorer bone quality.^3,4 The bone loss is greater in trabecular bone (eg, the femoral neck and vertebral bodies) than in cortical bone (eg, the forearm).⁵

Glucocorticoids have other systemic effects that increase fracture risk. For example, they cause muscle weakness and atrophy, increasing the risk of falls.⁴ Additionally, many of the inflammatory conditions for which they are prescribed (eg, rheumatoid arthritis) also increase the risk of osteoporosis by means of proinflammatory cytokine production, which may contribute to systemic and local effects on bone.^4,6

Bone mineral density declines quickly

Bone mineral density declines within the first 3 months after starting oral glucocorticoids, with the rate of bone loss peaking at 6 months. Up to 12% of bone mass is lost in the first year. In subsequent years of continued use, bone loss progresses at a slower, steadier rate, averaging 2% to 3% annually.^5,7,8

Oral therapy increases fracture risk

Kanis et al⁹ performed a meta-analysis of seven prospective cohort studies in 40,000 patients and found that the current or previous use of an oral glucocorticoid increased the risk of fragility fractures, and that men and women were  affected about equally.⁹

Van Staa et al^10,11 reported that daily doses of glucocorticoids equivalent to more than 2.5 mg of prednisone were associated with an increased risk of vertebral and hip fractures; fracture risk was related mainly to daily dosage rather than cumulative dose.

Van Staa et al,¹² in a retrospective cohort study, compared nearly 250,000 adult users of oral glucocorticoids from general medical practice settings with the same number of controls matched for sex, age, and medical practice. The relative risks for fractures and 95% confidence intervals (CIs) during oral glucocorticoid treatment were as follows:

• Forearm fracture 1.09 (1.01–1.17)
• Nonvertebral fracture 1.33 (1.29–1.38)
• Hip fracture 1.61 (1.47–1.76)
• Vertebral fracture 2.60 (2.31–2.92).

The risk was dose-dependent. For a low daily dose (< 2.5 mg/day of prednisolone), the relative risks were:

• Hip fracture 0.99 (0.82–1.20)
• Vertebral fracture 1.55 (1.20–2.01) .

For a medium daily dose (2.5–7.5 mg/day), the relative risks were: 

• Hip fracture 1.77 (1.55–2.02)
• Vertebral fracture 2.59 (2.16–3.10) .

For a high daily dose (> 7.5 mg/day), the relative risks were:

• Hip fracture 2.27 (1.94–2.66)
• Vertebral fracture 5.18 (4.25–6.31).

Fracture risk rapidly declined toward baseline after the patients stopped taking oral glucocorticoids but did not return to baseline levels. The lessening of excess fracture risk occurred mainly within the first year after stopping therapy.

Other studies^5,9,13 have suggested that the increased fracture risk is mostly independent of bone mineral density, and that other mechanisms are at play. One study¹⁴ found that oral glucocorticoid users with a prevalent vertebral fracture actually had higher bone mineral density than patients with a fracture not taking glucocorticoids, although this finding was not confirmed in a subsequent study.¹⁵

Inhaled glucocorticoids have less effect on bone

Inhaled glucocorticoids are commonly used to treat chronic obstructive pulmonary disease and asthma. They do not have the same systemic bioavailability as oral glucocorticoids, so the risk of adverse effects is lower.

Data are inconsistent among several studies that evaluated the relationship between inhaled glucocorticoids, bone mineral density, osteoporosis, and fragility fracture. The inconsistencies may be due to heterogeneity of the study populations, self-reporting of fractures, and different methods of assessing chronic obstructive pulmonary disease severity.¹⁶

A Cochrane review¹⁷ in 2002 evaluated seven randomized controlled trials that compared the use of inhaled glucocorticoids vs placebo in nearly 2,000 patients with mild asthma or chronic obstructive pulmonary disease and found no evidence for decreased bone mineral density, increased bone turnover, or increased vertebral fracture incidence in the glucocorticoid users at 2 to 3 years of follow-up (odds ratio for fracture 1.87, 95% CI 0.5–7.0).

The Evaluation of Obstructive Lung Disease and Osteoporosis study,¹⁶ a multicenter Italian observational epidemiologic study, reported that patients taking the highest daily doses of inhaled glucocorticoids (> 1,500 μg of beclomethasone or its equivalent) had a significantly higher risk of vertebral fracture (odds ratio 1.4, 95% CI 1.04–1.89).¹⁶

A meta-analysis¹⁸ of five case-control studies (43,783 cases and 259,936 controls) identified a possible dose-dependent relationship, with a relative risk for nonvertebral fracture of 1.12 (95% CI 1.0–1.26) for each 1,000-μg increase in beclomethasone-equivalent inhaled glucocorticoid per day.

In summary, the effects of inhaled glucocorticoids in adults are uncertain, although trends toward increased fracture risk and decreased bone mineral density are evident with chronic therapy at moderate to high dosages. The risks and benefits of treatment should be carefully considered in patients with osteoporosis and baseline elevated fracture risk.¹⁹

Managing the risk of glucocorticoid-induced osteoporosis

In 2010, the American College of Rheumatology published recommendations for preventing and treating glucocorticoid-induced osteoporosis, which were endorsed by the American Society for Bone and Mineral Research.²⁰ To lessen the risk of osteoporosis, the recommendations are as follows:

Limit exposure. Patients receiving glucocorticoids should be given the smallest dosage for the shortest duration possible.

Advise lifestyle changes. Patients should be counseled to limit their alcohol intake to no more than two drinks per day, to quit smoking, to engage in weight-bearing exercise, and to ingest enough calcium (1,200–1,500 mg/day, through diet and supplements) and vitamin D.

Monitor bone mineral density. Patients starting glucocorticoids at any dosage for an expected duration of at least 3 months should have their bone mineral density measured at baseline. The frequency of subsequent measurements should be based on the presence of other risk factors for fracture, results of previous bone density testing, glucocorticoid dosage, whether therapy for bone health has been initiated, and the rate of change in bone mineral density. If warranted and if the results would lead to a change in management, patients can undergo dual-energy x-ray absorptiometry more often than usual, ie, more often than every 2 years. Prevalent and incident fragility fractures, height measurements, fall risk assessments, laboratory measurements of 25-hydroxyvitamin D, and consideration of vertebral fracture assessment or other imaging of the spine, as necessary, should be part of counseling and monitoring.

Osteoporosis treatment. For patients who will be taking glucocorticoids for at least 3 months, alendronate, risedronate, zoledronic acid, or teriparatide can be initiated to prevent or treat osteoporosis in the following groups: 

• Postmenopausal women and men over age 50 if the daily glucocorticoid dosage is at least 7.5 mg/day or if the World Health Organization Fracture Risk Assessment Tool (FRAX) score is more than 10% (the threshold for medium fracture risk)
• Premenopausal women and men younger than 50 if they have a history of fragility fracture, the FRAX score is more than 20% (the threshold for high fracture risk), or the T score is less than –2.5.

Certain clinical factors can also put a patient into a higher-risk category. These include current tobacco use, low body mass index, parental history of hip fracture, consuming more than three alcoholic drinks daily, higher daily or cumulative glucocorticoid dosage, intravenous pulse glucocorticoid usage, or a decline in central bone mineral density that exceeds the least significant change according to the scanner used.²⁰

The FRAX tool accounts for bone density only at the femoral neck, and while useful, it cannot replace clinical judgment in stratifying risk. Moreover, it does not apply to premenopausal women or men under age 40.

The implicated medications have important roles, so weigh their risks and benefits

The long-term risks of medications to treat glucocorticoid-induced osteoporosis are not well defined for premenopausal women (or their unborn children) or in men younger than 40, so treatment is recommended in those groups only for those with prevalent fragility fractures who are clearly at higher risk of additional fractures.²⁰

PROTON PUMP INHIBITORS

Proton pump inhibitors are available by prescription and over the counter for gastric acid-related conditions. Concerns have been raised that these highly effective drugs are overused.²¹ Several of their adverse effects are self-limited and minor, but long-term use may entail serious risks, including propensity to bone fracture.²²

Low acid leads to poor calcium absorption

Why fracture risk increases with proton pump inhibitors is controversial and may relate to their desired effect of suppressing gastric acid production: calcium salts, including carbonate and chloride, are poorly soluble and require an acidic environment to increase calcium ionization and thus absorption.²³ For this reason, if patients taking a proton pump inhibitor take a calcium supplement, it should be calcium citrate, which unlike calcium carbonate does not require an acid environment for absorption.

Higher risk in older patients, with longer use, and with higher dosage

Since the first reports on proton pump inhibitors and fracture risk were published in 2006,^24,25 a number of studies have reported this association, including several systematic reviews.

In 2011, the US Food and Drug Administration (FDA) updated a 2010 safety communication based on seven epidemiologic studies reporting an increased risk of fractures of the spine, hip, and wrist with proton pump inhibitors.^24–31 Time of exposure to a proton pump inhibitor in these studies varied from 1 to 12 years. Fracture risk was higher in older patients,²⁶ with higher doses,^24,29 and with longer duration of drug use.^24,27 On the other hand, one study that included only patients without other major fracture risk factors failed to find an association between the use of proton pump inhibitors and fractures.²⁸

Is evidence sufficient for changing use?

The FDA report included a disclaimer that they had no access to study data or protocols and so could not verify the findings.²⁶ Moreover, the studies used claims data from computerized databases to evaluate the risk of fractures in patients treated with proton pump inhibitors compared with those not using these drugs.^24–31 Information was often incomplete regarding potentially important factors (eg, falls, family history of osteoporosis, calcium and vitamin D intake, smoking, alcohol use, reason for medication use), as well as the timing of drug use related to the onset or worsening of osteoporosis.²⁶

Although 34 published studies evaluated the association of fracture risk and proton pump inhibitors, Leontiadis and Moayyedi³² argued that insufficient evidence exists to change our prescribing habits for these drugs based on fracture risk, as the studies varied considerably in their designs and results, a clear dose-response relationship is lacking, and the modest association is likely related to multiple confounders.

Bottom line: Use with caution

Although the increased fracture risk associated with proton pump inhibitors is likely multifactorial and is not fully delineated, it appears to be real. These drugs should be used only if there is a clear indication for them and if their benefits likely outweigh their risks. The lowest effective dose should be used, and the need for continuing use should be frequently reassessed.

SELECTIVE SEROTONIN REUPTAKE INHIBITORS

Depression affects 1 in 10 people in the United States, is especially common in the elderly, and leads to significant morbidity and reduced quality of life.³³ Selective serotonin reuptake inhibitors (SSRIs) are often prescribed and are generally considered first-line agents for treating depression.

Complex bone effects

Use proton pump inhibitors only if there is a clear indication for them and their benefits likely outweigh the risks

SSRIs antagonize the serotonin transporter, which normally assists serotonin uptake from the extracellular space. The serotonin transporter is found in all main types of bone cells, including osteoclasts, osteoblasts, and osteocytes.³³ Serotonin is made by different genes in the brain than in the periphery, causing opposing effects on bone biology: when generated peripherally, it acts as a hormone to inhibit bone formation, while when generated in the brain, it acts as a neurotransmitter to create a major and positive effect on bone mass accrual by enhancing bone formation and limiting bone resorption.^34,35

Potential confounders complicate the effect of SSRIs on bone health, as depression itself may be a risk factor for fracture. Patients with depression tend to have increased inflammation and cortisol, decreased gonadal steroids, more behavioral risk factors such as tobacco and increased alcohol use, and less physical activity, all of which can contribute to low bone density and risk of falls and fractures.³³

Daily use of SSRIs increases fracture risk

A 2012 meta-analysis³⁶ of 12 studies (seven case-control and five cohort), showed that SSRI users had a higher overall risk of fracture (adjusted odds ratio 1.69, 95% CI 1.51–1.90). By anatomic site, pooled odds ratios and 95% CIs were:

• Vertebral fractures 1.34 (1.13–1.59)
• Wrist or forearm fractures 1.51 (1.26–1.82)
• Hip or femur fractures 2.06 (1.84–2.30). 

A 2013 meta-analysis³⁷ of 34 studies with more than 1 million patients found that the random-effects pooled relative risk of all fracture types in users of antidepressants (including but not limited to SSRIs) was 1.39 (95% CI 1.32–1.47) compared with nonusers. Relative risks and 95% CIs in antidepressant users were:

• Vertebral fractures 1.38 (1.19–1.61)
• Nonvertebral fractures 1.42 (1.34–1.51)
• Hip fractures 1.47 (1.36–1.58).

A population-based, prospective cohort study³⁸ of 5,008 community-dwelling adults age 50 and older, followed for 5 years, found that the daily use of SSRIs was associated with a twofold increased risk of clinical fragility fractures (defined as minimal trauma fractures that were clinically reported and radiographically confirmed) after adjusting for potential covariates. Daily SSRI use was also associated with an increased risk of falling (odds ratio 2.2, 95% CI 1.4–3.5), lower bone mineral density at the hip, and a trend toward lower bone mineral density at the spine. These effects were dose-dependent and were similar for those who reported taking SSRIs at baseline and at 5 years.

Bottom line: Counsel bone health

Although no guidelines exist for preventing or treating SSRI-induced bone loss, providers should discuss with patients the potential effect of these medications on bone health, taking into account patient age, severity of depression, sex, duration of use, length of SSRI treatment, and other clinical risk factors for osteoporosis.³⁴ Given the widespread use of these medications for treating depression, more study into this association is needed to further guide providers.

ANTIEPILEPTIC DRUGS

Antiepileptic drugs are used to treat not only seizure disorders but also migraine headaches, neuropathy, and psychiatric and pain disorders. Many studies have linked their use to an increased risk of fractures.

The mechanism of this effect remains controversial. Early studies reported that inducers of cytochrome P450 enzymes (eg, phenobarbital, phenytoin) lead to increased vitamin D degradation, causing osteomalacia.³⁹ Another study suggested that changes in calcium metabolism and reduced bone mineral density occur without vitamin D deficiency and that drugs such as valproate that do not induce cytochrome P450 enzymes may also affect bone health.⁴⁰ Other bone effects may include direct inhibition of intestinal calcium absorption (seen in animal studies) and the induction of a high remodeling state leading to osteomalacia.^41,42

Epilepsy itself increases risk of fractures

Patients with seizure disorders may also have an increased risk of fractures because of falls, trauma, impaired balance, use of glucocorticoids and benzodiazepines, and comorbid conditions (eg, mental retardation, cerebral palsy, and brain neoplasm).⁴³

A 2005 meta-analysis⁴³ of 11 studies of epilepsy and fracture risk and 12 studies of epilepsy and bone mineral density found that the risks of fractures were increased. The following relative risks and 95% CIs were noted:

The benefit of preventing seizures outweighs the risks of fractures

• Any fracture 2.2 (1.9–2.5), in five studies
• Forearm 1.7 (1.2–2.3), in six studies
• Hip 5.3 (3.2–8.8), six studies
• Spine 6.2 (2.5–15.5), in three studies.

A large proportion of fractures (35%) seemed related to seizures.

Certain drugs increase risk

A large 2004 population-based, case-control, study⁴⁴ (124,655 fracture cases and 373,962 controls) found an association between the use of antiepileptic drugs and increased fracture risk. After adjusting for current or prior use of glucocorticoids, prior fracture, social variables, comorbid conditions, and epilepsy diagnosis, excess fracture risk was found to be associated with the following drugs (odds ratios and 95% CIs):

• Oxcarbazepine 1.14 (1.03–1.26)
• Valproate 1.15 (1.05–1.26)
• Carbamazepine 1.18 (1.10-1.26)
• Phenobarbital 1.79 (1.64–1.95).

The risk was higher with higher doses. Fracture risk was higher with cytochrome P450 enzyme-inducing drugs (carbamazepine, oxcarbazepine, phenobarbital, phenytoin, and primidone; odds ratio 1.38, 95% CI 1.31–1.45) than for noninducing drugs (clonazepam, ethosuximide, lamotrigine, tiagabine, topiramate, valproate, and vigabatrin; odds ratio 1.19, 95% CI 1.11–1.27). No significant increased risk of fracture was found with use of phenytoin, tiagabine, topiramate, ethosuximide, lamotrigine, vigabatrin, or primidone after adjusting for confounders. 

Bottom line: Monitor bone health

With antiepileptic drugs, the benefit of preventing seizures outweighs the risks of fractures. Patients on long-term antiepileptic drug therapy should be monitored for bone mineral density and vitamin D levels and receive counseling on lifestyle measures including tobacco cessation, alcohol moderation, and fall prevention.⁴⁵ As there are no evidence-based guidelines for bone health in patients on antiepileptic drugs, management should be based on current guidelines for treating osteoporosis.

AROMATASE INHIBITORS

Depression itself may be a risk factor for fracture

Breast cancer is the most common cancer in women and is the second-leading cause of cancer-associated deaths in women after lung cancer. Aromatase inhibitors, such as anastrozole, letrozole, and exemestane, are the standard of care in adjuvant treatment for hormone-receptor-positive breast cancer, leading to longer disease-free survival.

However, aromatase inhibitors increase bone loss and fracture risk, and only partial recovery of bone mineral density occurs after treatment is stopped. The drugs deter the aromatization of androgens and their conversion to estrogens in peripheral tissue, leading to reduced estrogen levels and resulting bone loss.⁴⁶ Anastrozole and letrozole have been found to reduce bone mineral density, increase bone turnover, and increase the relative risk for nonvertebral and vertebral fractures in postmenopausal women by 40% compared with tamoxifen.^47,48

Base osteoporosis treatment on risk

Several groups have issued guidelines for preventing and treating bone loss in postmenopausal women being treated with an aromatase inhibitor. When initiating treatment, women should be counseled about modifiable risk factors, exercise, and calcium and vitamin D supplementation.

Baseline bone mineral testing should also be obtained when starting treatment. Hadji et al,⁴⁹ in a review article, recommend starting bone-directed therapy if the patient’s T score is less than –2.0 (using the lowest score from three sites) or if she has any of at least two of the following fracture risk factors:

• T score less than –1.5
• Age over 65
• Family history of hip fracture
• Personal history of fragility fracture after age 50
• Low body mass index (< 20 kg/m²)
• Current or prior history of tobacco use
• Oral glucocorticoid use for longer than 6 months.

Patients with a T score at or above –2.0 and no risk factors should have bone mineral density reassessed after 1 to 2 years. Antiresorptive therapy with intravenous zoledronic acid and evaluation for other secondary causes of bone loss should be initiated for either:

• An annual decrease of at least 10% or
• An annual decrease of at least 4% in patients with osteopenia at baseline.⁴⁹

In 2003, the American Society of Clinical Oncology updated its recommendations on the role of bisphosphonates and bone health in women with breast cancer.⁵⁰ They recommend the following:

• If the T score is –2.5 or less, prescribe a bisphosphonate (alendronate, risedronate, or zoledronic acid)
• If the T score is –1.0 to –2.5, tailor treatment individually and monitor bone mineral density annually
• If the T score is greater than –1.0, monitor bone mineral density annually.

All patients should receive lifestyle counseling, calcium and vitamin D supplementation, and monitoring of additional risk factors for osteoporosis as appropriate.⁵⁰

Drug-induced osteoporosis is common, and the list of drugs that can harm bone continues to grow. As part of routine health maintenance, practitioners should recognize the drugs that increase bone loss and take measures to mitigate these effects to help avoid osteopenia and osteoporosis.

Osteoporosis, a silent systemic disease defined by low bone mineral density and changes in skeletal microstructure, leads to a higher risk of fragility fractures. Some of the risk factors are well described, but less well known is the role of pharmacologic therapy. The implicated drugs (Table 1) have important therapeutic roles, so the benefits of using them must be weighed against their risks, including their potential effects on bone.

This review focuses on a few drugs known to increase fracture risk, their mechanisms of bone loss, and management considerations (Table 2).

GLUCOCORTICOIDS

Glucocorticoids are used to treat many medical conditions, including allergic, rheumatic, and other inflammatory diseases, and as immunosuppressive therapy after solid organ and bone marrow transplant. They are the most common cause of drug-induced bone loss and related secondary osteoporosis.

Multiple effects on bone

Glucocorticoids both increase bone resorption and decrease bone formation by a variety of mechanisms.¹ They reduce intestinal calcium absorption, increase urinary excretion of calcium, and enhance osteocyte apoptosis, leading to deterioration of the bone microarchitecture and bone mineral density.² They also affect sex hormones, decreasing testosterone production in men and estrogen in women, leading to increased bone resorption, altered bone architecture, and poorer bone quality.^3,4 The bone loss is greater in trabecular bone (eg, the femoral neck and vertebral bodies) than in cortical bone (eg, the forearm).⁵

Glucocorticoids have other systemic effects that increase fracture risk. For example, they cause muscle weakness and atrophy, increasing the risk of falls.⁴ Additionally, many of the inflammatory conditions for which they are prescribed (eg, rheumatoid arthritis) also increase the risk of osteoporosis by means of proinflammatory cytokine production, which may contribute to systemic and local effects on bone.^4,6

Bone mineral density declines quickly

Bone mineral density declines within the first 3 months after starting oral glucocorticoids, with the rate of bone loss peaking at 6 months. Up to 12% of bone mass is lost in the first year. In subsequent years of continued use, bone loss progresses at a slower, steadier rate, averaging 2% to 3% annually.^5,7,8

Oral therapy increases fracture risk

Kanis et al⁹ performed a meta-analysis of seven prospective cohort studies in 40,000 patients and found that the current or previous use of an oral glucocorticoid increased the risk of fragility fractures, and that men and women were  affected about equally.⁹

Van Staa et al^10,11 reported that daily doses of glucocorticoids equivalent to more than 2.5 mg of prednisone were associated with an increased risk of vertebral and hip fractures; fracture risk was related mainly to daily dosage rather than cumulative dose.

Van Staa et al,¹² in a retrospective cohort study, compared nearly 250,000 adult users of oral glucocorticoids from general medical practice settings with the same number of controls matched for sex, age, and medical practice. The relative risks for fractures and 95% confidence intervals (CIs) during oral glucocorticoid treatment were as follows:

• Forearm fracture 1.09 (1.01–1.17)
• Nonvertebral fracture 1.33 (1.29–1.38)
• Hip fracture 1.61 (1.47–1.76)
• Vertebral fracture 2.60 (2.31–2.92).

The risk was dose-dependent. For a low daily dose (< 2.5 mg/day of prednisolone), the relative risks were:

• Hip fracture 0.99 (0.82–1.20)
• Vertebral fracture 1.55 (1.20–2.01) .

For a medium daily dose (2.5–7.5 mg/day), the relative risks were: 

• Hip fracture 1.77 (1.55–2.02)
• Vertebral fracture 2.59 (2.16–3.10) .

For a high daily dose (> 7.5 mg/day), the relative risks were:

• Hip fracture 2.27 (1.94–2.66)
• Vertebral fracture 5.18 (4.25–6.31).

Fracture risk rapidly declined toward baseline after the patients stopped taking oral glucocorticoids but did not return to baseline levels. The lessening of excess fracture risk occurred mainly within the first year after stopping therapy.

Other studies^5,9,13 have suggested that the increased fracture risk is mostly independent of bone mineral density, and that other mechanisms are at play. One study¹⁴ found that oral glucocorticoid users with a prevalent vertebral fracture actually had higher bone mineral density than patients with a fracture not taking glucocorticoids, although this finding was not confirmed in a subsequent study.¹⁵

Inhaled glucocorticoids have less effect on bone

Inhaled glucocorticoids are commonly used to treat chronic obstructive pulmonary disease and asthma. They do not have the same systemic bioavailability as oral glucocorticoids, so the risk of adverse effects is lower.

Data are inconsistent among several studies that evaluated the relationship between inhaled glucocorticoids, bone mineral density, osteoporosis, and fragility fracture. The inconsistencies may be due to heterogeneity of the study populations, self-reporting of fractures, and different methods of assessing chronic obstructive pulmonary disease severity.¹⁶

A Cochrane review¹⁷ in 2002 evaluated seven randomized controlled trials that compared the use of inhaled glucocorticoids vs placebo in nearly 2,000 patients with mild asthma or chronic obstructive pulmonary disease and found no evidence for decreased bone mineral density, increased bone turnover, or increased vertebral fracture incidence in the glucocorticoid users at 2 to 3 years of follow-up (odds ratio for fracture 1.87, 95% CI 0.5–7.0).

The Evaluation of Obstructive Lung Disease and Osteoporosis study,¹⁶ a multicenter Italian observational epidemiologic study, reported that patients taking the highest daily doses of inhaled glucocorticoids (> 1,500 μg of beclomethasone or its equivalent) had a significantly higher risk of vertebral fracture (odds ratio 1.4, 95% CI 1.04–1.89).¹⁶

A meta-analysis¹⁸ of five case-control studies (43,783 cases and 259,936 controls) identified a possible dose-dependent relationship, with a relative risk for nonvertebral fracture of 1.12 (95% CI 1.0–1.26) for each 1,000-μg increase in beclomethasone-equivalent inhaled glucocorticoid per day.

In summary, the effects of inhaled glucocorticoids in adults are uncertain, although trends toward increased fracture risk and decreased bone mineral density are evident with chronic therapy at moderate to high dosages. The risks and benefits of treatment should be carefully considered in patients with osteoporosis and baseline elevated fracture risk.¹⁹

Managing the risk of glucocorticoid-induced osteoporosis

In 2010, the American College of Rheumatology published recommendations for preventing and treating glucocorticoid-induced osteoporosis, which were endorsed by the American Society for Bone and Mineral Research.²⁰ To lessen the risk of osteoporosis, the recommendations are as follows:

Limit exposure. Patients receiving glucocorticoids should be given the smallest dosage for the shortest duration possible.

Advise lifestyle changes. Patients should be counseled to limit their alcohol intake to no more than two drinks per day, to quit smoking, to engage in weight-bearing exercise, and to ingest enough calcium (1,200–1,500 mg/day, through diet and supplements) and vitamin D.

Monitor bone mineral density. Patients starting glucocorticoids at any dosage for an expected duration of at least 3 months should have their bone mineral density measured at baseline. The frequency of subsequent measurements should be based on the presence of other risk factors for fracture, results of previous bone density testing, glucocorticoid dosage, whether therapy for bone health has been initiated, and the rate of change in bone mineral density. If warranted and if the results would lead to a change in management, patients can undergo dual-energy x-ray absorptiometry more often than usual, ie, more often than every 2 years. Prevalent and incident fragility fractures, height measurements, fall risk assessments, laboratory measurements of 25-hydroxyvitamin D, and consideration of vertebral fracture assessment or other imaging of the spine, as necessary, should be part of counseling and monitoring.

Osteoporosis treatment. For patients who will be taking glucocorticoids for at least 3 months, alendronate, risedronate, zoledronic acid, or teriparatide can be initiated to prevent or treat osteoporosis in the following groups: 

• Postmenopausal women and men over age 50 if the daily glucocorticoid dosage is at least 7.5 mg/day or if the World Health Organization Fracture Risk Assessment Tool (FRAX) score is more than 10% (the threshold for medium fracture risk)
• Premenopausal women and men younger than 50 if they have a history of fragility fracture, the FRAX score is more than 20% (the threshold for high fracture risk), or the T score is less than –2.5.

Certain clinical factors can also put a patient into a higher-risk category. These include current tobacco use, low body mass index, parental history of hip fracture, consuming more than three alcoholic drinks daily, higher daily or cumulative glucocorticoid dosage, intravenous pulse glucocorticoid usage, or a decline in central bone mineral density that exceeds the least significant change according to the scanner used.²⁰

The FRAX tool accounts for bone density only at the femoral neck, and while useful, it cannot replace clinical judgment in stratifying risk. Moreover, it does not apply to premenopausal women or men under age 40.

The implicated medications have important roles, so weigh their risks and benefits

The long-term risks of medications to treat glucocorticoid-induced osteoporosis are not well defined for premenopausal women (or their unborn children) or in men younger than 40, so treatment is recommended in those groups only for those with prevalent fragility fractures who are clearly at higher risk of additional fractures.²⁰

PROTON PUMP INHIBITORS

Proton pump inhibitors are available by prescription and over the counter for gastric acid-related conditions. Concerns have been raised that these highly effective drugs are overused.²¹ Several of their adverse effects are self-limited and minor, but long-term use may entail serious risks, including propensity to bone fracture.²²

Low acid leads to poor calcium absorption

Why fracture risk increases with proton pump inhibitors is controversial and may relate to their desired effect of suppressing gastric acid production: calcium salts, including carbonate and chloride, are poorly soluble and require an acidic environment to increase calcium ionization and thus absorption.²³ For this reason, if patients taking a proton pump inhibitor take a calcium supplement, it should be calcium citrate, which unlike calcium carbonate does not require an acid environment for absorption.

Higher risk in older patients, with longer use, and with higher dosage

Since the first reports on proton pump inhibitors and fracture risk were published in 2006,^24,25 a number of studies have reported this association, including several systematic reviews.

In 2011, the US Food and Drug Administration (FDA) updated a 2010 safety communication based on seven epidemiologic studies reporting an increased risk of fractures of the spine, hip, and wrist with proton pump inhibitors.^24–31 Time of exposure to a proton pump inhibitor in these studies varied from 1 to 12 years. Fracture risk was higher in older patients,²⁶ with higher doses,^24,29 and with longer duration of drug use.^24,27 On the other hand, one study that included only patients without other major fracture risk factors failed to find an association between the use of proton pump inhibitors and fractures.²⁸

Is evidence sufficient for changing use?

The FDA report included a disclaimer that they had no access to study data or protocols and so could not verify the findings.²⁶ Moreover, the studies used claims data from computerized databases to evaluate the risk of fractures in patients treated with proton pump inhibitors compared with those not using these drugs.^24–31 Information was often incomplete regarding potentially important factors (eg, falls, family history of osteoporosis, calcium and vitamin D intake, smoking, alcohol use, reason for medication use), as well as the timing of drug use related to the onset or worsening of osteoporosis.²⁶

Although 34 published studies evaluated the association of fracture risk and proton pump inhibitors, Leontiadis and Moayyedi³² argued that insufficient evidence exists to change our prescribing habits for these drugs based on fracture risk, as the studies varied considerably in their designs and results, a clear dose-response relationship is lacking, and the modest association is likely related to multiple confounders.

Bottom line: Use with caution

Although the increased fracture risk associated with proton pump inhibitors is likely multifactorial and is not fully delineated, it appears to be real. These drugs should be used only if there is a clear indication for them and if their benefits likely outweigh their risks. The lowest effective dose should be used, and the need for continuing use should be frequently reassessed.

SELECTIVE SEROTONIN REUPTAKE INHIBITORS

Depression affects 1 in 10 people in the United States, is especially common in the elderly, and leads to significant morbidity and reduced quality of life.³³ Selective serotonin reuptake inhibitors (SSRIs) are often prescribed and are generally considered first-line agents for treating depression.

Complex bone effects

Use proton pump inhibitors only if there is a clear indication for them and their benefits likely outweigh the risks

SSRIs antagonize the serotonin transporter, which normally assists serotonin uptake from the extracellular space. The serotonin transporter is found in all main types of bone cells, including osteoclasts, osteoblasts, and osteocytes.³³ Serotonin is made by different genes in the brain than in the periphery, causing opposing effects on bone biology: when generated peripherally, it acts as a hormone to inhibit bone formation, while when generated in the brain, it acts as a neurotransmitter to create a major and positive effect on bone mass accrual by enhancing bone formation and limiting bone resorption.^34,35

Potential confounders complicate the effect of SSRIs on bone health, as depression itself may be a risk factor for fracture. Patients with depression tend to have increased inflammation and cortisol, decreased gonadal steroids, more behavioral risk factors such as tobacco and increased alcohol use, and less physical activity, all of which can contribute to low bone density and risk of falls and fractures.³³

Daily use of SSRIs increases fracture risk

A 2012 meta-analysis³⁶ of 12 studies (seven case-control and five cohort), showed that SSRI users had a higher overall risk of fracture (adjusted odds ratio 1.69, 95% CI 1.51–1.90). By anatomic site, pooled odds ratios and 95% CIs were:

• Vertebral fractures 1.34 (1.13–1.59)
• Wrist or forearm fractures 1.51 (1.26–1.82)
• Hip or femur fractures 2.06 (1.84–2.30). 

A 2013 meta-analysis³⁷ of 34 studies with more than 1 million patients found that the random-effects pooled relative risk of all fracture types in users of antidepressants (including but not limited to SSRIs) was 1.39 (95% CI 1.32–1.47) compared with nonusers. Relative risks and 95% CIs in antidepressant users were:

• Vertebral fractures 1.38 (1.19–1.61)
• Nonvertebral fractures 1.42 (1.34–1.51)
• Hip fractures 1.47 (1.36–1.58).

A population-based, prospective cohort study³⁸ of 5,008 community-dwelling adults age 50 and older, followed for 5 years, found that the daily use of SSRIs was associated with a twofold increased risk of clinical fragility fractures (defined as minimal trauma fractures that were clinically reported and radiographically confirmed) after adjusting for potential covariates. Daily SSRI use was also associated with an increased risk of falling (odds ratio 2.2, 95% CI 1.4–3.5), lower bone mineral density at the hip, and a trend toward lower bone mineral density at the spine. These effects were dose-dependent and were similar for those who reported taking SSRIs at baseline and at 5 years.

Bottom line: Counsel bone health

Although no guidelines exist for preventing or treating SSRI-induced bone loss, providers should discuss with patients the potential effect of these medications on bone health, taking into account patient age, severity of depression, sex, duration of use, length of SSRI treatment, and other clinical risk factors for osteoporosis.³⁴ Given the widespread use of these medications for treating depression, more study into this association is needed to further guide providers.

ANTIEPILEPTIC DRUGS

Antiepileptic drugs are used to treat not only seizure disorders but also migraine headaches, neuropathy, and psychiatric and pain disorders. Many studies have linked their use to an increased risk of fractures.

The mechanism of this effect remains controversial. Early studies reported that inducers of cytochrome P450 enzymes (eg, phenobarbital, phenytoin) lead to increased vitamin D degradation, causing osteomalacia.³⁹ Another study suggested that changes in calcium metabolism and reduced bone mineral density occur without vitamin D deficiency and that drugs such as valproate that do not induce cytochrome P450 enzymes may also affect bone health.⁴⁰ Other bone effects may include direct inhibition of intestinal calcium absorption (seen in animal studies) and the induction of a high remodeling state leading to osteomalacia.^41,42

Epilepsy itself increases risk of fractures

Patients with seizure disorders may also have an increased risk of fractures because of falls, trauma, impaired balance, use of glucocorticoids and benzodiazepines, and comorbid conditions (eg, mental retardation, cerebral palsy, and brain neoplasm).⁴³

A 2005 meta-analysis⁴³ of 11 studies of epilepsy and fracture risk and 12 studies of epilepsy and bone mineral density found that the risks of fractures were increased. The following relative risks and 95% CIs were noted:

The benefit of preventing seizures outweighs the risks of fractures

• Any fracture 2.2 (1.9–2.5), in five studies
• Forearm 1.7 (1.2–2.3), in six studies
• Hip 5.3 (3.2–8.8), six studies
• Spine 6.2 (2.5–15.5), in three studies.

A large proportion of fractures (35%) seemed related to seizures.

Certain drugs increase risk

A large 2004 population-based, case-control, study⁴⁴ (124,655 fracture cases and 373,962 controls) found an association between the use of antiepileptic drugs and increased fracture risk. After adjusting for current or prior use of glucocorticoids, prior fracture, social variables, comorbid conditions, and epilepsy diagnosis, excess fracture risk was found to be associated with the following drugs (odds ratios and 95% CIs):

• Oxcarbazepine 1.14 (1.03–1.26)
• Valproate 1.15 (1.05–1.26)
• Carbamazepine 1.18 (1.10-1.26)
• Phenobarbital 1.79 (1.64–1.95).

The risk was higher with higher doses. Fracture risk was higher with cytochrome P450 enzyme-inducing drugs (carbamazepine, oxcarbazepine, phenobarbital, phenytoin, and primidone; odds ratio 1.38, 95% CI 1.31–1.45) than for noninducing drugs (clonazepam, ethosuximide, lamotrigine, tiagabine, topiramate, valproate, and vigabatrin; odds ratio 1.19, 95% CI 1.11–1.27). No significant increased risk of fracture was found with use of phenytoin, tiagabine, topiramate, ethosuximide, lamotrigine, vigabatrin, or primidone after adjusting for confounders. 

Bottom line: Monitor bone health

With antiepileptic drugs, the benefit of preventing seizures outweighs the risks of fractures. Patients on long-term antiepileptic drug therapy should be monitored for bone mineral density and vitamin D levels and receive counseling on lifestyle measures including tobacco cessation, alcohol moderation, and fall prevention.⁴⁵ As there are no evidence-based guidelines for bone health in patients on antiepileptic drugs, management should be based on current guidelines for treating osteoporosis.

AROMATASE INHIBITORS

Depression itself may be a risk factor for fracture

Breast cancer is the most common cancer in women and is the second-leading cause of cancer-associated deaths in women after lung cancer. Aromatase inhibitors, such as anastrozole, letrozole, and exemestane, are the standard of care in adjuvant treatment for hormone-receptor-positive breast cancer, leading to longer disease-free survival.

However, aromatase inhibitors increase bone loss and fracture risk, and only partial recovery of bone mineral density occurs after treatment is stopped. The drugs deter the aromatization of androgens and their conversion to estrogens in peripheral tissue, leading to reduced estrogen levels and resulting bone loss.⁴⁶ Anastrozole and letrozole have been found to reduce bone mineral density, increase bone turnover, and increase the relative risk for nonvertebral and vertebral fractures in postmenopausal women by 40% compared with tamoxifen.^47,48

Base osteoporosis treatment on risk

Several groups have issued guidelines for preventing and treating bone loss in postmenopausal women being treated with an aromatase inhibitor. When initiating treatment, women should be counseled about modifiable risk factors, exercise, and calcium and vitamin D supplementation.

Baseline bone mineral testing should also be obtained when starting treatment. Hadji et al,⁴⁹ in a review article, recommend starting bone-directed therapy if the patient’s T score is less than –2.0 (using the lowest score from three sites) or if she has any of at least two of the following fracture risk factors:

• T score less than –1.5
• Age over 65
• Family history of hip fracture
• Personal history of fragility fracture after age 50
• Low body mass index (< 20 kg/m²)
• Current or prior history of tobacco use
• Oral glucocorticoid use for longer than 6 months.

Patients with a T score at or above –2.0 and no risk factors should have bone mineral density reassessed after 1 to 2 years. Antiresorptive therapy with intravenous zoledronic acid and evaluation for other secondary causes of bone loss should be initiated for either:

• An annual decrease of at least 10% or
• An annual decrease of at least 4% in patients with osteopenia at baseline.⁴⁹

In 2003, the American Society of Clinical Oncology updated its recommendations on the role of bisphosphonates and bone health in women with breast cancer.⁵⁰ They recommend the following:

• If the T score is –2.5 or less, prescribe a bisphosphonate (alendronate, risedronate, or zoledronic acid)
• If the T score is –1.0 to –2.5, tailor treatment individually and monitor bone mineral density annually
• If the T score is greater than –1.0, monitor bone mineral density annually.

All patients should receive lifestyle counseling, calcium and vitamin D supplementation, and monitoring of additional risk factors for osteoporosis as appropriate.⁵⁰

Confronted with the unexpected results of two trials of vertebroplasty,^1,2 physicians are feeling some consternation, We had thought that percutaneous vertebroplasty helps patients with osteoporosis who sustain a painful vertebral insufficiency fracture. However, the trials found it to be no better than a sham procedure in terms of relieving pain.

See related commentary

How will these findings affect our practice? Should we abandon this popular procedure? Or are there other considerations that may mitigate these negative findings? And what should we tell our patients?

700,000 FRACTURES PER YEAR

Vertebral insufficiency fractures are the most common type of fracture in patients with osteoporosis. Every year in the United States, about 700,000 of them occur.

Nearly two-thirds are asymptomatic. The other one-third typically present with the acute onset of localized pain.

Vertebral insufficiency fractures often lead to chronic pain, impair the ability to walk and to perform daily activities, and accentuate thoracic kyphosis, which in turn can lead to pulmonary restrictive disease, and they raise the risk of death. Also, a patient who has a vertebral insufficiency fracture has a 20% risk of sustaining a new one within 1 year.³

Whether symptomatic or asymptomatic, finding a vertebral insufficiency fracture should prompt one to consider drug therapy for osteoporosis. In addition, until now, a patient who presented with the acute onset of back pain and whose evaluation revealed a vertebral insufficiency fracture would also be considered for a vertebral augmentation procedure, either vertebroplasty or kyphoplasty, to relieve the pain.

Vertebroplasty involves injecting polymethylmethacrylate cement percutaneously into the affected vertebral body. Kyphoplasty, a similar procedure, uses a balloon to create a cavity in the fractured vertebral body. After the balloon is withdrawn, the cavity is filled with cement.

TWO RANDOMIZED TRIALS OF SHAM VS REAL VERTEBROPLASTY

Two teams, Kallmes et al² and Buchbinder et al,¹ independently performed randomized controlled trials to see if vertebroplasty really relieves pain as well as has been reported in open studies, case series, and nonrandomized trials.^4–7

In both trials, patients were randomized to undergo either sham vertebroplasty or real vertebroplasty. The sham procedure closely approximated the real procedure, including inserting a needle, infiltrating a local anesthetic, bupivacaine (Marcaine), into the periosteum of the posterior lamina¹ or the pedicle of the target vertebrae,² and opening a vial of polymethylmethacrylate so that the patient would smell the product.

Inclusion criteria

Patients in both trials had to have evidence of a recent (acute) or nonhealed vertebral insufficiency fracture.

Pain was the primary outcome measured

In both trials, the investigators assessed the patients’ pain at baseline and again at several specified intervals, using validated tools.

Kallmes et al assessed pain intensity and functional measures at 1 month (the primary outcome measured), and also at 3, 14, and 90 days and at 1 year.

Buchbinder et al assessed pain at 1 week and at 1, 3, and 6 months. The primary outcome measured was pain at 3 months. Secondary outcomes included quality-of-life measures, pain at rest, and pain at night.

Surprising results

In both trials, the mean pain scores were better than at baseline at all time points after the procedure in both the real-procedure and the sham-procedure groups. Moreover, the effect did not differ between the two treatment groups in either study.

QUESTIONS COMPLICATE THE ISSUE

These two trials should make us consider whether this intervention is warranted. We should, however, also consider some limitations of these studies that raise questions about how the conclusions should or should not alter practice.

Does local anesthetic continue to relieve pain?

In both the sham and the real procedure, the bupivacaine injection may have helped relieve pain to some extent afterward, as its anesthetic effect may last longer than we would expect from its 3-hour half-life. The effect could certainly have contributed to improvements in pain levels at the earlier time points after the procedure.

Was there selection bias?

Both studies were highly rigorous and were done at hospitals that had extensive experience with vertebroplasty. However, they may have harbored selection bias, as many more patients were screened than were randomized.

Buchbinder et al¹ screened 468 patients. Of these, 30% declined to participate, and another 53% did not meet the eligibility criteria. In the end, only 78 patients were randomized.

Kallmes et al² screened 1,813 patients, 300 of whom declined and 1,382 of whom were excluded, leaving 131 patients to be randomized. The reasons for exclusion were not specifically reported in many cases.

In both studies, it would be interesting to know how many of those who declined proceeded to undergo a vertebral augmentation procedure.

In the study by Kallmes et al,² recruitment got off to a slow start. Thus, after three patients were recruited, the inclusion requirements were liberalized. The study was originally designed to include 250 patients, which would have given it a power of greater than 80% to detect differences in primary and secondary outcomes. The design was revised to include 130 patients. The statistical power was still 80%, but this was to detect a greater difference in the outcomes than originally projected.

Had the window of opportunity already closed?

Vertebroplasty may have a window of opportunity within which it is most effective. Sooner is probably better than later, but it would be good to identify this time frame.

Kaufmann et al⁹ reported that patients with older fractures needed slightly more analgesic drugs after the procedure. It has been shown previously that patients who are the most likely to respond to a vertebral augmentation procedure are those with fractures that occurred between 1 and 12 months prior to the procedure and who have evidence that the fracture was recent, ie, edema on magnetic resonance imaging (MRI) or increased uptake on a bone scan.¹⁰

Other studies suggested that intervention works best in patients who have had uncontrolled pain lasting less than 6 weeks.^8,11 (In the study by Buchbinder et al,¹ only 32% of the patients in either group reported pain lasting less than 6 weeks.)

The study by Kallmes et al included patients whose pain had begun within 1 year previously. However, if the duration of pain (ie, the age of the fracture) was uncertain, MRI was done to look for edema, which would indicate the fracture was fresh. It is thus unclear whether all patients in this study truly had an acute or subacute fracture, since all did not undergo confirmatory MRI.

Why did so many patients cross over from sham to real treatment?

Patients in the Kallmes trial² could cross over from one treatment group to the other as early as 1 month after the procedure. And, in fact, 43% of patients in the sham-treatment group did choose to cross over by 3 months. In contrast, after real vertebroplasty, significantly fewer—only 12% (P < .001)—crossed over to receive the sham procedure. The patients who crossed over from the sham-procedure group to receive vertebroplasty experienced an early improvement in pain, but this was not sustained at 1 or 3 months of follow-up.

The higher crossover rate in the shamprocedure group suggests they were dissatisfied with this intervention, although their outcomes were not significantly better after they got the real procedure. The patients who first received the sham treatment and elected to cross over to vertebroplasty had higher pain and disability scores at baseline. Thus, they may have had other, more chronic causes of pain or other factors affecting the likelihood of a response, particularly of a durable or sustained response.

How do the interventions compare with medical therapy?

Earlier studies showed that vertebroplasty relieves pain almost immediately.^4–6 But the benefit does not last: at 6 weeks and up to 12 months later there is no difference in either pain or functional capacity reported in patients receiving vertebroplasty vs conservative treatment.^4,6,7 It would thus appear that pain gradually diminishes over time after a vertebral insufficiency fracture, as the fracture heals.

The recent studies^1,2 raise the possibility that the pain relief is due to the local anesthetic, not the vertebroplasty itself. We do not know, however, if either vertebroplasty or the sham procedure is superior to conservative medical management. Prospective multicenter trials are under way to address this question.¹¹

Further complicating the issue, the two trials did not keep track of medical treatments patients were receiving concomitantly during the trial period. It is thus more difficult to compare the pain assessment outcomes following invasive procedures—real or sham.

Would kyphoplasty be better?

These studies addressed one procedure, vertebroplasty, and the results and conclusions should not be generalized to kyphoplasty. A prospective randomized trial of kyphoplasty is clearly warranted.

If kyphoplasty is found to be better than a sham procedure, then vertebroplasty should be re-examined in comparison with kyphoplasty. In any future studies, it will be important to select patients rigorously (eg, to include only patients with recent fractures), to match patients according to concomitant therapies, and to consider other potential superimposed causes of back pain in this elderly population, which has a high prevalence of back pain.

HOW SHOULD MY PRACTICE CHANGE? WHAT SHOULD I TELL PATIENTS?

Having considered the results, conclusions, and limitations of these two randomized trials, particularly in terms of recruitment, I cannot say that my practice has changed in terms of referring patients who have a vertebral compression fracture to an interventionalist. However, the education that I provide to patients has changed.

In my mind, the highest priority for a patient with a vertebral insufficiency fracture is to treat (or to reassess the current treatment of) the underlying systemic disease, ie, osteoporosis. This is especially true since most vertebral insufficiency fractures are asymptomatic.

On the other hand, a patient with a painful vertebral compression fracture needs prompt attention and consideration for interventional pain relief. Rapid pain relief is desirable. And in uncontrolled trials,^4–7 vertebroplasty and kyphoplasty rapidly relieved vertebral pain. However, it may be that an anesthetic injection is equivalent to vertebroplasty and could accomplish the goal of immediate pain relief just as well.

The pain relief from sham or real vertebroplasty may not be durable, and 3 to 12 months later the pain benefit may be no greater than if more conservative therapy had been pursued.

It is essential to determine the most appropriate window for treatment as well as the most appropriate candidates on whom to perform a procedure. The recently published studies^1,2 may have had significant patient selection bias and may not have optimized the window of opportunity for vertebral augmentation performance. There were many patients who declined the study, and some were excluded because of acute pain requiring hospitalization.

As a rheumatologist treating patients with osteoporosis, it is my responsibility to discuss with the patient and family the potential treatments available, to discuss the associated possible risks and benefits, to report on available evidence, and to refer patients to an appropriate interventional specialist if they desire. In light of the lack of superior pain reduction with vertebroplasty than with a sham procedure, many patients may opt for conservative therapy.

It is thus appropriate to determine the acuity of the fracture and to have a frank discussion with the patient about the options for pain management. Opiate drugs pose risks in elderly patients, particularly altered mentation, somnolence, interference with balance, and risk of falls. Vertebroplasty or anesthetic injection may rapidly relieve the pain and reduce the need for opiate therapy. Not yet subjected to the rigors of a randomized placebocontrolled trial, kyphoplasty may yet prove to be better than a sham intervention.

It is essential to determine if there is a role for vertebral augmentation in a select patient population—perhaps selected on the basis of the time that has elapsed since the fracture occurred (determined objectively), the severity of the fracture, and other factors. Perhaps a subset of patients would gain greater benefit from the procedure, whether it amounts solely to acute pain reduction or perhaps to a more durable response.

The recent studies by Kallmes et al² and Buchbinder et al¹ found vertebroplasty and sham vertebroplasty to be equally effective in reducing pain and improving function. However, given the limitations of each of these studies, particularly the low numbers of patients, it is difficult to establish that vertebral augmentation procedures should no longer be done. And vertebroplasty may still benefit correctly selected patients.

Confronted with the unexpected results of two trials of vertebroplasty,^1,2 physicians are feeling some consternation, We had thought that percutaneous vertebroplasty helps patients with osteoporosis who sustain a painful vertebral insufficiency fracture. However, the trials found it to be no better than a sham procedure in terms of relieving pain.

See related commentary

How will these findings affect our practice? Should we abandon this popular procedure? Or are there other considerations that may mitigate these negative findings? And what should we tell our patients?

700,000 FRACTURES PER YEAR

Vertebral insufficiency fractures are the most common type of fracture in patients with osteoporosis. Every year in the United States, about 700,000 of them occur.

Nearly two-thirds are asymptomatic. The other one-third typically present with the acute onset of localized pain.

Vertebral insufficiency fractures often lead to chronic pain, impair the ability to walk and to perform daily activities, and accentuate thoracic kyphosis, which in turn can lead to pulmonary restrictive disease, and they raise the risk of death. Also, a patient who has a vertebral insufficiency fracture has a 20% risk of sustaining a new one within 1 year.³

Whether symptomatic or asymptomatic, finding a vertebral insufficiency fracture should prompt one to consider drug therapy for osteoporosis. In addition, until now, a patient who presented with the acute onset of back pain and whose evaluation revealed a vertebral insufficiency fracture would also be considered for a vertebral augmentation procedure, either vertebroplasty or kyphoplasty, to relieve the pain.

Vertebroplasty involves injecting polymethylmethacrylate cement percutaneously into the affected vertebral body. Kyphoplasty, a similar procedure, uses a balloon to create a cavity in the fractured vertebral body. After the balloon is withdrawn, the cavity is filled with cement.

TWO RANDOMIZED TRIALS OF SHAM VS REAL VERTEBROPLASTY

Two teams, Kallmes et al² and Buchbinder et al,¹ independently performed randomized controlled trials to see if vertebroplasty really relieves pain as well as has been reported in open studies, case series, and nonrandomized trials.^4–7

In both trials, patients were randomized to undergo either sham vertebroplasty or real vertebroplasty. The sham procedure closely approximated the real procedure, including inserting a needle, infiltrating a local anesthetic, bupivacaine (Marcaine), into the periosteum of the posterior lamina¹ or the pedicle of the target vertebrae,² and opening a vial of polymethylmethacrylate so that the patient would smell the product.

Inclusion criteria

Patients in both trials had to have evidence of a recent (acute) or nonhealed vertebral insufficiency fracture.

Pain was the primary outcome measured

In both trials, the investigators assessed the patients’ pain at baseline and again at several specified intervals, using validated tools.

Kallmes et al assessed pain intensity and functional measures at 1 month (the primary outcome measured), and also at 3, 14, and 90 days and at 1 year.

Buchbinder et al assessed pain at 1 week and at 1, 3, and 6 months. The primary outcome measured was pain at 3 months. Secondary outcomes included quality-of-life measures, pain at rest, and pain at night.

Surprising results

In both trials, the mean pain scores were better than at baseline at all time points after the procedure in both the real-procedure and the sham-procedure groups. Moreover, the effect did not differ between the two treatment groups in either study.

QUESTIONS COMPLICATE THE ISSUE

These two trials should make us consider whether this intervention is warranted. We should, however, also consider some limitations of these studies that raise questions about how the conclusions should or should not alter practice.

Does local anesthetic continue to relieve pain?

In both the sham and the real procedure, the bupivacaine injection may have helped relieve pain to some extent afterward, as its anesthetic effect may last longer than we would expect from its 3-hour half-life. The effect could certainly have contributed to improvements in pain levels at the earlier time points after the procedure.

Was there selection bias?

Both studies were highly rigorous and were done at hospitals that had extensive experience with vertebroplasty. However, they may have harbored selection bias, as many more patients were screened than were randomized.

Buchbinder et al¹ screened 468 patients. Of these, 30% declined to participate, and another 53% did not meet the eligibility criteria. In the end, only 78 patients were randomized.

Kallmes et al² screened 1,813 patients, 300 of whom declined and 1,382 of whom were excluded, leaving 131 patients to be randomized. The reasons for exclusion were not specifically reported in many cases.

In both studies, it would be interesting to know how many of those who declined proceeded to undergo a vertebral augmentation procedure.

In the study by Kallmes et al,² recruitment got off to a slow start. Thus, after three patients were recruited, the inclusion requirements were liberalized. The study was originally designed to include 250 patients, which would have given it a power of greater than 80% to detect differences in primary and secondary outcomes. The design was revised to include 130 patients. The statistical power was still 80%, but this was to detect a greater difference in the outcomes than originally projected.

Had the window of opportunity already closed?

Vertebroplasty may have a window of opportunity within which it is most effective. Sooner is probably better than later, but it would be good to identify this time frame.

Kaufmann et al⁹ reported that patients with older fractures needed slightly more analgesic drugs after the procedure. It has been shown previously that patients who are the most likely to respond to a vertebral augmentation procedure are those with fractures that occurred between 1 and 12 months prior to the procedure and who have evidence that the fracture was recent, ie, edema on magnetic resonance imaging (MRI) or increased uptake on a bone scan.¹⁰

Other studies suggested that intervention works best in patients who have had uncontrolled pain lasting less than 6 weeks.^8,11 (In the study by Buchbinder et al,¹ only 32% of the patients in either group reported pain lasting less than 6 weeks.)

The study by Kallmes et al included patients whose pain had begun within 1 year previously. However, if the duration of pain (ie, the age of the fracture) was uncertain, MRI was done to look for edema, which would indicate the fracture was fresh. It is thus unclear whether all patients in this study truly had an acute or subacute fracture, since all did not undergo confirmatory MRI.

Why did so many patients cross over from sham to real treatment?

Patients in the Kallmes trial² could cross over from one treatment group to the other as early as 1 month after the procedure. And, in fact, 43% of patients in the sham-treatment group did choose to cross over by 3 months. In contrast, after real vertebroplasty, significantly fewer—only 12% (P < .001)—crossed over to receive the sham procedure. The patients who crossed over from the sham-procedure group to receive vertebroplasty experienced an early improvement in pain, but this was not sustained at 1 or 3 months of follow-up.

The higher crossover rate in the shamprocedure group suggests they were dissatisfied with this intervention, although their outcomes were not significantly better after they got the real procedure. The patients who first received the sham treatment and elected to cross over to vertebroplasty had higher pain and disability scores at baseline. Thus, they may have had other, more chronic causes of pain or other factors affecting the likelihood of a response, particularly of a durable or sustained response.

How do the interventions compare with medical therapy?

Earlier studies showed that vertebroplasty relieves pain almost immediately.^4–6 But the benefit does not last: at 6 weeks and up to 12 months later there is no difference in either pain or functional capacity reported in patients receiving vertebroplasty vs conservative treatment.^4,6,7 It would thus appear that pain gradually diminishes over time after a vertebral insufficiency fracture, as the fracture heals.

The recent studies^1,2 raise the possibility that the pain relief is due to the local anesthetic, not the vertebroplasty itself. We do not know, however, if either vertebroplasty or the sham procedure is superior to conservative medical management. Prospective multicenter trials are under way to address this question.¹¹

Further complicating the issue, the two trials did not keep track of medical treatments patients were receiving concomitantly during the trial period. It is thus more difficult to compare the pain assessment outcomes following invasive procedures—real or sham.

Would kyphoplasty be better?

These studies addressed one procedure, vertebroplasty, and the results and conclusions should not be generalized to kyphoplasty. A prospective randomized trial of kyphoplasty is clearly warranted.

If kyphoplasty is found to be better than a sham procedure, then vertebroplasty should be re-examined in comparison with kyphoplasty. In any future studies, it will be important to select patients rigorously (eg, to include only patients with recent fractures), to match patients according to concomitant therapies, and to consider other potential superimposed causes of back pain in this elderly population, which has a high prevalence of back pain.

HOW SHOULD MY PRACTICE CHANGE? WHAT SHOULD I TELL PATIENTS?

Having considered the results, conclusions, and limitations of these two randomized trials, particularly in terms of recruitment, I cannot say that my practice has changed in terms of referring patients who have a vertebral compression fracture to an interventionalist. However, the education that I provide to patients has changed.

In my mind, the highest priority for a patient with a vertebral insufficiency fracture is to treat (or to reassess the current treatment of) the underlying systemic disease, ie, osteoporosis. This is especially true since most vertebral insufficiency fractures are asymptomatic.

On the other hand, a patient with a painful vertebral compression fracture needs prompt attention and consideration for interventional pain relief. Rapid pain relief is desirable. And in uncontrolled trials,^4–7 vertebroplasty and kyphoplasty rapidly relieved vertebral pain. However, it may be that an anesthetic injection is equivalent to vertebroplasty and could accomplish the goal of immediate pain relief just as well.

The pain relief from sham or real vertebroplasty may not be durable, and 3 to 12 months later the pain benefit may be no greater than if more conservative therapy had been pursued.

It is essential to determine the most appropriate window for treatment as well as the most appropriate candidates on whom to perform a procedure. The recently published studies^1,2 may have had significant patient selection bias and may not have optimized the window of opportunity for vertebral augmentation performance. There were many patients who declined the study, and some were excluded because of acute pain requiring hospitalization.

As a rheumatologist treating patients with osteoporosis, it is my responsibility to discuss with the patient and family the potential treatments available, to discuss the associated possible risks and benefits, to report on available evidence, and to refer patients to an appropriate interventional specialist if they desire. In light of the lack of superior pain reduction with vertebroplasty than with a sham procedure, many patients may opt for conservative therapy.

It is thus appropriate to determine the acuity of the fracture and to have a frank discussion with the patient about the options for pain management. Opiate drugs pose risks in elderly patients, particularly altered mentation, somnolence, interference with balance, and risk of falls. Vertebroplasty or anesthetic injection may rapidly relieve the pain and reduce the need for opiate therapy. Not yet subjected to the rigors of a randomized placebocontrolled trial, kyphoplasty may yet prove to be better than a sham intervention.

It is essential to determine if there is a role for vertebral augmentation in a select patient population—perhaps selected on the basis of the time that has elapsed since the fracture occurred (determined objectively), the severity of the fracture, and other factors. Perhaps a subset of patients would gain greater benefit from the procedure, whether it amounts solely to acute pain reduction or perhaps to a more durable response.

The recent studies by Kallmes et al² and Buchbinder et al¹ found vertebroplasty and sham vertebroplasty to be equally effective in reducing pain and improving function. However, given the limitations of each of these studies, particularly the low numbers of patients, it is difficult to establish that vertebral augmentation procedures should no longer be done. And vertebroplasty may still benefit correctly selected patients.

Confronted with the unexpected results of two trials of vertebroplasty,^1,2 physicians are feeling some consternation, We had thought that percutaneous vertebroplasty helps patients with osteoporosis who sustain a painful vertebral insufficiency fracture. However, the trials found it to be no better than a sham procedure in terms of relieving pain.

See related commentary

How will these findings affect our practice? Should we abandon this popular procedure? Or are there other considerations that may mitigate these negative findings? And what should we tell our patients?

700,000 FRACTURES PER YEAR

Vertebral insufficiency fractures are the most common type of fracture in patients with osteoporosis. Every year in the United States, about 700,000 of them occur.

Nearly two-thirds are asymptomatic. The other one-third typically present with the acute onset of localized pain.

Vertebral insufficiency fractures often lead to chronic pain, impair the ability to walk and to perform daily activities, and accentuate thoracic kyphosis, which in turn can lead to pulmonary restrictive disease, and they raise the risk of death. Also, a patient who has a vertebral insufficiency fracture has a 20% risk of sustaining a new one within 1 year.³

Whether symptomatic or asymptomatic, finding a vertebral insufficiency fracture should prompt one to consider drug therapy for osteoporosis. In addition, until now, a patient who presented with the acute onset of back pain and whose evaluation revealed a vertebral insufficiency fracture would also be considered for a vertebral augmentation procedure, either vertebroplasty or kyphoplasty, to relieve the pain.

Vertebroplasty involves injecting polymethylmethacrylate cement percutaneously into the affected vertebral body. Kyphoplasty, a similar procedure, uses a balloon to create a cavity in the fractured vertebral body. After the balloon is withdrawn, the cavity is filled with cement.

TWO RANDOMIZED TRIALS OF SHAM VS REAL VERTEBROPLASTY

Two teams, Kallmes et al² and Buchbinder et al,¹ independently performed randomized controlled trials to see if vertebroplasty really relieves pain as well as has been reported in open studies, case series, and nonrandomized trials.^4–7

In both trials, patients were randomized to undergo either sham vertebroplasty or real vertebroplasty. The sham procedure closely approximated the real procedure, including inserting a needle, infiltrating a local anesthetic, bupivacaine (Marcaine), into the periosteum of the posterior lamina¹ or the pedicle of the target vertebrae,² and opening a vial of polymethylmethacrylate so that the patient would smell the product.

Inclusion criteria

Patients in both trials had to have evidence of a recent (acute) or nonhealed vertebral insufficiency fracture.

Pain was the primary outcome measured

In both trials, the investigators assessed the patients’ pain at baseline and again at several specified intervals, using validated tools.

Kallmes et al assessed pain intensity and functional measures at 1 month (the primary outcome measured), and also at 3, 14, and 90 days and at 1 year.

Buchbinder et al assessed pain at 1 week and at 1, 3, and 6 months. The primary outcome measured was pain at 3 months. Secondary outcomes included quality-of-life measures, pain at rest, and pain at night.

Surprising results

In both trials, the mean pain scores were better than at baseline at all time points after the procedure in both the real-procedure and the sham-procedure groups. Moreover, the effect did not differ between the two treatment groups in either study.

QUESTIONS COMPLICATE THE ISSUE

These two trials should make us consider whether this intervention is warranted. We should, however, also consider some limitations of these studies that raise questions about how the conclusions should or should not alter practice.

Does local anesthetic continue to relieve pain?

In both the sham and the real procedure, the bupivacaine injection may have helped relieve pain to some extent afterward, as its anesthetic effect may last longer than we would expect from its 3-hour half-life. The effect could certainly have contributed to improvements in pain levels at the earlier time points after the procedure.

Was there selection bias?

Both studies were highly rigorous and were done at hospitals that had extensive experience with vertebroplasty. However, they may have harbored selection bias, as many more patients were screened than were randomized.

Buchbinder et al¹ screened 468 patients. Of these, 30% declined to participate, and another 53% did not meet the eligibility criteria. In the end, only 78 patients were randomized.

Kallmes et al² screened 1,813 patients, 300 of whom declined and 1,382 of whom were excluded, leaving 131 patients to be randomized. The reasons for exclusion were not specifically reported in many cases.

In both studies, it would be interesting to know how many of those who declined proceeded to undergo a vertebral augmentation procedure.

In the study by Kallmes et al,² recruitment got off to a slow start. Thus, after three patients were recruited, the inclusion requirements were liberalized. The study was originally designed to include 250 patients, which would have given it a power of greater than 80% to detect differences in primary and secondary outcomes. The design was revised to include 130 patients. The statistical power was still 80%, but this was to detect a greater difference in the outcomes than originally projected.

Had the window of opportunity already closed?

Vertebroplasty may have a window of opportunity within which it is most effective. Sooner is probably better than later, but it would be good to identify this time frame.

Kaufmann et al⁹ reported that patients with older fractures needed slightly more analgesic drugs after the procedure. It has been shown previously that patients who are the most likely to respond to a vertebral augmentation procedure are those with fractures that occurred between 1 and 12 months prior to the procedure and who have evidence that the fracture was recent, ie, edema on magnetic resonance imaging (MRI) or increased uptake on a bone scan.¹⁰

Other studies suggested that intervention works best in patients who have had uncontrolled pain lasting less than 6 weeks.^8,11 (In the study by Buchbinder et al,¹ only 32% of the patients in either group reported pain lasting less than 6 weeks.)

The study by Kallmes et al included patients whose pain had begun within 1 year previously. However, if the duration of pain (ie, the age of the fracture) was uncertain, MRI was done to look for edema, which would indicate the fracture was fresh. It is thus unclear whether all patients in this study truly had an acute or subacute fracture, since all did not undergo confirmatory MRI.

Why did so many patients cross over from sham to real treatment?

Patients in the Kallmes trial² could cross over from one treatment group to the other as early as 1 month after the procedure. And, in fact, 43% of patients in the sham-treatment group did choose to cross over by 3 months. In contrast, after real vertebroplasty, significantly fewer—only 12% (P < .001)—crossed over to receive the sham procedure. The patients who crossed over from the sham-procedure group to receive vertebroplasty experienced an early improvement in pain, but this was not sustained at 1 or 3 months of follow-up.

The higher crossover rate in the shamprocedure group suggests they were dissatisfied with this intervention, although their outcomes were not significantly better after they got the real procedure. The patients who first received the sham treatment and elected to cross over to vertebroplasty had higher pain and disability scores at baseline. Thus, they may have had other, more chronic causes of pain or other factors affecting the likelihood of a response, particularly of a durable or sustained response.

How do the interventions compare with medical therapy?

Earlier studies showed that vertebroplasty relieves pain almost immediately.^4–6 But the benefit does not last: at 6 weeks and up to 12 months later there is no difference in either pain or functional capacity reported in patients receiving vertebroplasty vs conservative treatment.^4,6,7 It would thus appear that pain gradually diminishes over time after a vertebral insufficiency fracture, as the fracture heals.

The recent studies^1,2 raise the possibility that the pain relief is due to the local anesthetic, not the vertebroplasty itself. We do not know, however, if either vertebroplasty or the sham procedure is superior to conservative medical management. Prospective multicenter trials are under way to address this question.¹¹

Further complicating the issue, the two trials did not keep track of medical treatments patients were receiving concomitantly during the trial period. It is thus more difficult to compare the pain assessment outcomes following invasive procedures—real or sham.

Would kyphoplasty be better?

These studies addressed one procedure, vertebroplasty, and the results and conclusions should not be generalized to kyphoplasty. A prospective randomized trial of kyphoplasty is clearly warranted.

If kyphoplasty is found to be better than a sham procedure, then vertebroplasty should be re-examined in comparison with kyphoplasty. In any future studies, it will be important to select patients rigorously (eg, to include only patients with recent fractures), to match patients according to concomitant therapies, and to consider other potential superimposed causes of back pain in this elderly population, which has a high prevalence of back pain.

HOW SHOULD MY PRACTICE CHANGE? WHAT SHOULD I TELL PATIENTS?

Having considered the results, conclusions, and limitations of these two randomized trials, particularly in terms of recruitment, I cannot say that my practice has changed in terms of referring patients who have a vertebral compression fracture to an interventionalist. However, the education that I provide to patients has changed.

In my mind, the highest priority for a patient with a vertebral insufficiency fracture is to treat (or to reassess the current treatment of) the underlying systemic disease, ie, osteoporosis. This is especially true since most vertebral insufficiency fractures are asymptomatic.

On the other hand, a patient with a painful vertebral compression fracture needs prompt attention and consideration for interventional pain relief. Rapid pain relief is desirable. And in uncontrolled trials,^4–7 vertebroplasty and kyphoplasty rapidly relieved vertebral pain. However, it may be that an anesthetic injection is equivalent to vertebroplasty and could accomplish the goal of immediate pain relief just as well.

The pain relief from sham or real vertebroplasty may not be durable, and 3 to 12 months later the pain benefit may be no greater than if more conservative therapy had been pursued.

It is essential to determine the most appropriate window for treatment as well as the most appropriate candidates on whom to perform a procedure. The recently published studies^1,2 may have had significant patient selection bias and may not have optimized the window of opportunity for vertebral augmentation performance. There were many patients who declined the study, and some were excluded because of acute pain requiring hospitalization.

As a rheumatologist treating patients with osteoporosis, it is my responsibility to discuss with the patient and family the potential treatments available, to discuss the associated possible risks and benefits, to report on available evidence, and to refer patients to an appropriate interventional specialist if they desire. In light of the lack of superior pain reduction with vertebroplasty than with a sham procedure, many patients may opt for conservative therapy.

It is thus appropriate to determine the acuity of the fracture and to have a frank discussion with the patient about the options for pain management. Opiate drugs pose risks in elderly patients, particularly altered mentation, somnolence, interference with balance, and risk of falls. Vertebroplasty or anesthetic injection may rapidly relieve the pain and reduce the need for opiate therapy. Not yet subjected to the rigors of a randomized placebocontrolled trial, kyphoplasty may yet prove to be better than a sham intervention.

It is essential to determine if there is a role for vertebral augmentation in a select patient population—perhaps selected on the basis of the time that has elapsed since the fracture occurred (determined objectively), the severity of the fracture, and other factors. Perhaps a subset of patients would gain greater benefit from the procedure, whether it amounts solely to acute pain reduction or perhaps to a more durable response.

The recent studies by Kallmes et al² and Buchbinder et al¹ found vertebroplasty and sham vertebroplasty to be equally effective in reducing pain and improving function. However, given the limitations of each of these studies, particularly the low numbers of patients, it is difficult to establish that vertebral augmentation procedures should no longer be done. And vertebroplasty may still benefit correctly selected patients.