Treatment of osteoporosis with annual iv zoledronic acid: effects on hip fracture

Roland D Chapurlat

INSERM U831, Université de Lyon, Division of Rheumatology, Hôpital E Herriot, Hospices Civils de Lyon, Lyon, France

Background: Several treatments for postmenopausal osteoporosis have been available in the past decade, but adherence to these treatments has been judged inadequate. The prevention of hip fracture by these medications is still modest.

Methods: A literature search was performed for treatment with zoledronic acid for the prevention of hip fracture.

Results: In the The Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly (HORIZON) Pivotal Fracture Trial, involving 7765 postmenopausal women with low bone mineral density or with prevalent vertebral fracture, women taking zoledronic acid had a 41% relative risk reduction for hip fracture, at 3 years, compared to placebo. In the HORIZON Recurrent Fracture Trial, 2127 patients (76% were women) were randomized to receive either zoledronic acid or placebo after sustaining a first hip fracture. A reduction of 30% in the second hip fracture risk was observed, but it did not reach statistical significance. Zoledronic acid was generally safe in these trials, although a slightly increased rate of severe atrial fibrillations was observed in the HORIZON Prevention Fracture Trial, but not in the HORIZON Recurrent Fracture Trial.

Conclusion: Yearly zoledronic acid reduces the risk of hip fracture, both in postmenopausal osteoporotic women with and without prevalent vertebral fracture and in men and women with a recent first hip fracture.

Keywords: osteoporosis, bisphosphonates, hip fracture, zoledronic acid