Quoted from http://www.latimes.com/features/health/la-he-closer-20100322,5,4989919.story
Take bisphosphonates, break a leg?
Though two reports contend a connection exists between taking the drugs over a long period of time and getting these fractures, the FDA says so such connection exists.
By Jill U. Adams
Special to the Los Angeles Times
March 22, 2010
Long-term use of osteoporosis drugs seems to change bones in a way that could lead to unusual leg fractures, according to two reports presented earlier this month at a meeting of orthopedic surgeons. Doctors have reported seeing the unusual fractures in some patients on bisphosphonate drugs such as Fosamax.
It seems paradoxical that a medicine designed to protect against bone fractures in fact might be the cause of broken legs. Adding to the confusion, the U.S. Food and Drug Administration released a statement in the same week as the medical conference that said there is no clear connection, based on available evidence, between the bisphosphonates — including Actonel, Boniva and Reclast in addition to Fosamax — and atypical femur fractures.
The unusual bone breaks — called atypical subtrochanteric femur fractures — were first documented in small clinical reports and through the FDA's MedWatch system, which monitors side effects of drugs after they've been approved. Such reports do not necessarily mean the drug is the cause of the problem, but multiple reports of the same side effect with the same drug can spur additional investigation. Other potential side effects of bisphosphonate drugs have been identified through the FDA's reporting system, including serious jaw deterioration and esophageal cancer.
Here's a closer look at what's known about the safety and effectiveness of bisphosphonates.