Some dentists say that they are seeing an increase in patients with a painful jaw condition which may be associated with the osteoporosis drug Fosamax. The condition, known as osteonecrosis of the jaw, or jaw necrosis, causes the death of jawbone tissue. Patients with this extremely painful condition may eventually need to have their jawbone removed in order to this potential side effect of Fosamax.

Osteonecrosis of the jaw has been linked to bisphosphonates, a class of drugs which includes Fosamax. Initially, doctors believed that only cancer patients taking Fosamax or a similar drug intravenously were at risk of developing jaw necrosis; however, researchers now believe that patients taking the drug orally may also be at risk of Fosamax side effects.

Many of the patients who have suffered jaw necrosis first began to experience side effects of Fosamax after undergoing a dental procedure. As a result, the American Dental Association has advised dentists to avoid invasive procedures on cancer patients who are receiving Fosamax intravenously, and to use caution on patients taking the drug orally.

As of May 2005, at least 800 cases if osteonecrosis of the jaw had been reported to the Food and Drug Administration by patients who had suffered Fosamax side effects. Fifteen of these patients who were diagnosed with jaw necrosis have filed Fosamax lawsuits against Merck & Co., the drug’s manufacturer.