Quoted from http://www.businessweek.com/lifestyle/content/healthday/644359.html
Bone Drugs Linked to Rare Fractures, FDA Warns
Agency to change warning label, issue medication guide for all bisphosphonates used to treat osteoporosis
By Steven Reinberg
HealthDay Reporter
WEDNESDAY, Oct. 13 (HealthDay News) -- People taking drugs called bisphosphonates, such as Fosamax and Boniva, to prevent or treat osteoporosis may be at risk for a rare type of fracture of the thigh bone, U.S. health officials warned Wednesday.
Bisphosphonates work by inhibiting bone loss and have been shown to prevent fractures due to osteoporosis. Whether bisphosphonates are the cause of these rare thigh fractures isn't clear, but they have predominantly been reported in patients taking these drugs, according to the U.S. Food and Drug Administration (FDA).
"FDA is warning again about the possible risk of an uncommon form of fracture in patients who take bisphosphonates to treat or prevent osteoporosis," Rear Admiral Sandra Kweder, M.D., deputy director of CDC's Office of New Drugs, Center for Drug Evaluation and Research, said during an afternoon press conference Wednesday.
The warning will take the form of a label change and a medication guide that patients will receive with their prescription, she said.
One of the unusual features of these atypical thigh fractures, also called atypical femur fractures, is that they are often associated with little or no trauma, Kweder said.