Efficacy of risedronate on clinical vertebral fractures within six months

SUMMARYObjective:Postmenopausal osteoporotic women with pre-existing or new incident vertebral fractures are at high risk for future fracture, so prompt treatment is warranted. Risedronate has been shown to reduce the incidence of radiographically-defined vertebral fractures by approximately two-thirds within 1 year.Research design:This study examined the effects of risedronate treatment on the time course of the reduction in the risk of clinical vertebral fractures (i.e., symptomatic fractures), on the risk of moderate-to-severe radiographic vertebral fractures, and on height.Results:In 2442 postmenopausal women with prevalent vertebral fractures from the Vertebral Efficacy with Risedronate Therapy (VERT) studies who received either risedronate 5 mg or placebo, daily risedronate reduced the risk of clinical vertebral fractures within 6 months (RR 0.08, 95 CI 0.01-0.63), and by 69 at 1 year (RR 0.31, 95 CI 0.12, 0.78). At 1 year, risedronate also reduced the risk of moderate-to-severe radiographically-defined vertebral fractures by 71 (RR 0.29 95 CI 0.16, 0.54). Height loss was attenuated with treatment, most notably in patients who experienced new vertebral fractures, with a median difference of 0.73 cm compared with subjects receiving placebo ( p 0.005).Conclusion:Risedronate reduces the risk of clinical vertebral fractures in postmenopausal women with osteoporosis within 6 months of commencing treatment.