Alendronate in PMR: Bone Protection, Not Disease Treatment
Alendronate is not used to treat polymyalgia rheumatica itself, but rather to prevent glucocorticoid-induced osteoporosis in PMR patients requiring prolonged corticosteroid therapy. The standard dose is 10 mg daily or 70 mg weekly. 1
Role of Alendronate in PMR Management
Alendronate serves as prophylaxis against bone loss from glucocorticoid therapy, not as a disease-modifying agent for PMR:
Glucocorticoids remain the sole first-line treatment for PMR, with initial prednisone doses of 12.5-25 mg daily strongly recommended by EULAR/ACR guidelines. 1
Osteoporosis assessment is mandatory before initiating glucocorticoid therapy, as PMR patients typically require prolonged treatment (often >1 year) and are at high risk for glucocorticoid-induced bone loss. 1
Bisphosphonate prophylaxis should be considered early in patients with risk factors including female sex, age >65 years, prior fractures, or baseline osteoporosis. 1
Dosing and Efficacy
The evidence for alendronate in glucocorticoid-induced osteoporosis is robust:
Standard dosing is 10 mg daily (or 70 mg weekly equivalent), which has been validated in multiple randomized controlled trials of patients on chronic glucocorticoid therapy. 2, 3
Bone density improvements are significant: Alendronate increases lumbar spine BMD by 2.1-2.9% and femoral neck BMD by 1.0-1.2% over 48 weeks compared to placebo, which shows bone loss. 4, 2
Fracture reduction trends favorably with relative risk of 0.6 for new vertebral fractures, though individual studies lack statistical power to definitively prove fracture prevention. 4, 2
Clinical Implementation in PMR
Real-world practice patterns reveal significant underutilization:
Only 46% of PMR patients receive bisphosphonates despite guidelines recommending prophylaxis in >90% of cases requiring prolonged glucocorticoid therapy. 5
Female sex, BMD testing, and treatment after 2005 are associated with higher bisphosphonate prescription rates, suggesting awareness has improved but remains suboptimal. 5
Initiate bisphosphonates at the first visit when starting glucocorticoids, rather than waiting for documented bone loss, as prevention is more effective than treatment. 3, 5
Safety Profile
Alendronate is well-tolerated in this population:
No increased overall adverse events compared to placebo in glucocorticoid-treated patients. 4, 2
Gastrointestinal side effects are actually reduced (RR 0.77) in meta-analysis, contrary to common concerns. 4
Minor increase in upper GI effects with 10 mg daily dosing is non-serious and manageable. 2
Common Pitfalls to Avoid
Do not delay bisphosphonate initiation until bone loss is documented—bone loss begins immediately upon starting glucocorticoids. 3
Do not rely solely on calcium and vitamin D—while these should be co-administered, they are insufficient alone to prevent glucocorticoid-induced osteoporosis. 5
Do not forget male patients—though women are at higher risk, men on chronic glucocorticoids also benefit from bisphosphonate prophylaxis. 2, 5
Do not assume short-term glucocorticoid use is safe—bone loss occurs rapidly, and PMR typically requires 1-2 years of treatment with frequent relapses necessitating dose increases. 1