Side Effect Watch: Femur Fractures in Fosamax Patients

-WSJ

12/03/2008- A study in the current issue of the Journal of Orthopedic Trauma links Merck’s osteoporosis drug Fosamax to a rare type of fracture in the femur. The small, observational study looked at 70 patients who experienced low-energy femur fractures, which occur when someone falls from a standing height or less. Twenty-five patients (36%) were taking Fosamax on average for four years or more.

The Fosamax patients’ fractures had some distinct characteristics: Nineteen (76%) of the 25 patients had a simple fracture with a straight line across the bone and and a beak-like overhang on one side. Also, the patients’ bones didn’t look like typical osteoporotic bone; it looked strong.

Andrew Neviaser, lead author of the paper and a third-year surgical resident at the Hospital for Special Surgery in N.Y. cautioned against patients or doctors hitting the panic button. “I don’t think it’s appropriate to cast Fosamax as a bad drug. It’s a very, very good drug that literally saves peoples’ lives by preventing hip fractures,” he told the Health Blog. But the study may highlight the fact that some patients who take the drug are vulnerable to fractures. And doctors, he says, should be vigilant in keeping tabs on patients who take these meds.

Merck pointed out that Fosamax and other drugs in its class, known as bisphosphonates, have been shown to decrease the risk of a type of femur fractures common in patients with osteoporosis. In a statement on the new study, Merck said that “a causal association with bisphosphonates and either the fracture pattern or the frequency of these fractures has not been established by the authors.”

This isn’t the first time that Fosamax has been linked to rare side effects in a small number of patients—there’s pending litigation against Fosamax maker Merck from people alleging the drug caused their jaw bones to erode. And in January, the WSJ reported the first non-jaw injury lawsuit brought by a woman claiming the drug caused stress fractures in her legs.