Single annual injectable treatment for postmenopausal osteoporosis

Abstract

Background: Several treatments for postmenopausal osteoporosis have become available over the last decade, but adherence to treatment is inadequate and the prevention of non-vertebral fracture by those medications is still modest. Methods: We have performed a literature search regarding treatment with zoledronic acid in postmenopausal women. Results: In the 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 70% vertebral fracture relative risk reduction and 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 a placebo after sustaining an initial hip fracture. After a median follow-up of 1.9 years, a relative risk reduction of 35% of clinical fractures was observed. Death from all causes was reduced by 28% in the zoledronic acid group. Zoledronic acid was generally safe in those trials, although a slightly increased rate of severe atrial fibrillations was observed in the HORIZON Prevention Fracture Trial, although not in the HORIZON Recurrent Fracture Trial. The clinical significance of this remains unclear. Conclusion: Yearly zoledronic acid presents a new option for the treatment of postmenopausal osteoporosis, with the perspective of improving the long-term persistence of therapy because of its once-a-year regimen.