The FOSAMAX Induced Femur Fractures - HB Litigation Conferences

Black 2010: Risk of atypical femur fractures
This study combined results of 3 large prior placebo-controlled studies of
bisphosphonates: FIT (3-4.5 years on Fosamax, 5 mg for first 2 years, then 10 mg)
and FLEX (additional up to 5 years on Fosamax) and HORIZON (up to 3 years on
annual zolendronic acid). Among 14,195 women, 284 records showed hip or femur
fractures, of which 12 were classified as subtrochanteric or diaphyseal, a combined
rate of 2.3 per 10,000 patient-years.
The authors calculated that treating 1,000 women with BPs for 3 years would prevent
100 fractures, while the risk of atypical femur fractures would be about 0.3 cases.
“The occurrence of [such] fractures of the femur was very rare, even among women
who had been treated with bisphosphonates for as long as 10 years. There was no
significant increase associated with bisphosphonate use, but the study was
underpowered for definitive conclusions.”
-Black et al., 2010. Bisphosphonates and fracture of the subtrochanteric or
diaphyseal femur. New England J Medicine 361:1761-71.