Popular Osteoporosis Drugs Found To Triple Risk of Bone Necrosis

A recent study has found that a popular class of osteoporosis drugs nearly triples the risk of developing bone necrosis, a condition that can lead to disfigurement and debilitating pain.

The study, performed by investigators from University of British Columbia (UBC; Vancouver, Canada) and Vancouver Coastal Health Research Institute (VCHRI; Canada), is the largest study of bone necrosis and bisphosphonates, a class of drugs used by millions of women worldwide to help prevent bone fractures due to osteoporosis. It is also the first study to explore the link between bone necrosis and specific brands of bisphosphonates, such as Actonel, Didrocal, and Fosamax. Researchers found that all three brands had similar outcomes.

Bone necrosis, a relatively rare disease, leads to permanent loss of blood supply to the bones. Without adequate blood supply, the bone tissue dies and causes the bone to collapse. The disease primarily affects shoulders, knees and hips at the joints, causing severe pain and immobility.

Published online in the Journal of Rheumatology on January 29, 2008, the findings follow a recent U.S. Food and Drug Administration (FDA) alert about bisphosphonates that highlighted the possibility of severe and sometimes incapacitating bone, joint, or muscle pain in patients taking the drugs.

According to the American Dental Association, more than 190 million prescriptions have been written for bisphosphonates worldwide. The drugs are promoted in direct-to-consumer advertisements on U.S. television stations. "The message for women taking these medications is to pay attention to your pain,” said lead investigator Dr. Mahyar Etminan of the Center for Clinical Epidemiology and Evaluation at UBC and VCHRI. "Given the widespread use of these drugs, it is important that women and their doctors know the risks that come with taking them.”

Dr. Etminan cautioned that bisphosphonate use might increase in the future as the possible link between estrogen use and breast cancer prompts women to switch from estrogen therapy to bisphosphonate therapy to prevent osteoporotic bone fractures. Another reason may be the availability of new bisphosphonates that come in once-a-month or once-a-year doses.

The epidemiologic study, a collaboration between UBC, VCHRI, and McGill University (Montreal, Canada), is based on the health records of 88,000 Quebec residents from 1996 to 2003. The team undertook the research after academic studies began linking necrosis of the jaw with the use of bisphosphonates.

"This is particularly important work,” said Dr. John Esdaile, professor and head of rheumatology, UBC and scientific director, Arthritis Research Center of Canada located at VCHRI's Center for Hip Health. "Although the osteonecrosis side-effect is rare, the use of the bisphosphonates is very common, people taking bisphosphonates are now hearing about the potential side-effects, and this study result will permit physicians to better inform them what the order of magnitude of the risk may be.”


Related Links:
University of British Columbia
Vancouver Coastal Health Research Institute
FDA Alert