Bisphosphonates: Postmarketing study data

Researchers at the university and colleagues reported data showing that there was a high prevalence of current bisphosphonate use among Swedish women with atypical subtrochanteric or shaft fractures but that the magnitude of the absolute risk was small. Specifically, 46 (78%) of 59 patients with atypical fractures had used bisphosphonates during the 3 years prior to the fracture compared with 26 (10%) of 263 control patients with ordinary fractures. The difference in the risk of atypical fracture between users and nonusers of bisphosphonates was 5 cases per 10,000 patient-years.

The risk was higher with a longer duration of use, and decreased after drug withdrawal. The risk appeared to be unrelated to systemic glucocorticoids and other drugs with effects on bone, and was independent of coexisting conditions and age. The researchers concluded that benefits of fracture prevention with bisphosphonate use greatly outweigh the risk of atypical femoral fracture. Data were published in the New England Journal of Medicine. ...