Fosamax (generic name: alendronate sodium) is a type of drug known as a bisphosphonate. Bisphosphonates are commonly used in tablet form such as Fosamax to prevent and treat osteoporosis in post-menopausal women.

Stronger forms of bisphosphonates are commonly used in the management of advanced cancers that have metastasized to the bone, where the disease often causes bone pain and possibly even fractures. Such cancers include lung cancer, breast cancer, prostate cancer, multiple myeloma, and others. When bisphosphonates are given in cancer chemotherapy, the drugs are given intravenously and usually for longer periods of time. A connection has been found between bisphosphonates and a serious bone disease called osteonecrosis of the jaw (ONJ), also known as Dead Jaw.

This finding was published in the Journal of Oral and Maxillofacial Surgeons . It prompted both the Food and Drug Administration (FDA) and Novartis, the manufacturer of bisphosphonates used in cancer chemotherapy, to issue a warning to health care professionals. The September 24, 2004 warning letter contained information about bisphosphonates and the risks of osteonecrosis in the jaw.

Osteonecrosis of the jaw (ONJ) is a condition in which the bone tissue in the jaw fails to heal after minor trauma such as a tooth extraction, causing the bone to be exposed. The exposure can eventually lead to infection and fracture and may require long-term antibiotic therapy or surgery to remove the dying bone tissue. Experts say that prevention and early treatment of those using bisphosphonates such as Fosamax is extremely important in preserving the jaw bone. Individuals using Fosomax or other bisphosphonates should attempt to steer clear of tooth extractions and other major dental work while on the drugs.