Biphosphanates information and side effects, risk, danger, osteonecrosis of the jaw by Ray Sahelian, M.D.

Biphosphonates are a class of drugs that inhibits the resorption of bone. Biphosphanates are used for the prevention and treatment of osteoporosis, osteitis deformans ("Paget's disease of bone"), bone metastasis, multiple myeloma and other conditions that involve bone fragility. In the last 10 years, millions of patients have taken biphosphanates for the prevention of osteoporosis. Biphosphantes once seemed safe and may have been helpful for patients with cancer or osteoporosis. But, at what risk?
 

Biphosphanate side effects, danger, risks, safety profile
The potential side effects of biphosphanates began in 2003 with a letter in The Journal of Oral Maxillofacial Surgery calling osteonecrosis of the jaw "a growing epidemic." Its author, Dr. Robert E. Marx, chief of oral and maxillofacial surgery at the University of Miami, reported on 36 patients who had received intravenous biphosphanates. All had "painful bone exposure," as is typical with the condition, and "were unresponsive to surgical or medical treatments."
     Many women have been taking biphosphanates thinking that these drugs were safe. However, there may be a risk for  osteonecrosis of the jaw. Osteonecrosis of the jaw is an uncommon complication, but it is estimated that among the 500,000 American cancer patients who take the drugs because their disease is affecting their bones, 1 to 10 percent may develop the problem. Some dentists are refusing to treat patients taking the drugs, fearful that the dental work will induce a case of osteonecrosis, and lawyers are lining up to sue the drugs' makers, saying they failed to give patients adequate warning.
     Even if patients stop taking the biphosphanate drugs, they are not free of them. Biphosphanates remain in bone for years, and no one knows how long the osteonecrosis risk remains. Some doctors and dentists suggest stopping the drugs for a few months before and after an invasive dental procedure. Others say six months to a year may be better.

Biphosphonate associated osteonecrosis of the jaw
Journal of Rheumatology 36 (3), 478-90 (March 2009)
In 2003, the first reports describing osteonecrosis of the jaw in patients receiving biphosphonates were published. These cases occurred in patients with cancer receiving high-dose intravenous biphosphonates; however, 5% of the cases were in patients with osteoporosis receiving low-dose bisphosphonate therapy. We present the results of a systematic review of the incidence, risk factors, diagnosis, prevention, and treatment of bisphosphonates associated ONJ. We conducted a comprehensive literature search for relevant studies on biphosphonates associated osteonecrosis of the jaw in oncology and osteoporosis patients published before February 2008. In oncology patients receiving high-dose intravenous bisphosphonates, ONJ appears to be dependent on the dose and duration of therapy, with an estimated incidence of 1%-12% at 36 months of exposure. In osteoporosis patients, it is rare, with an estimated incidence<1 case per 100,000 person-years of exposure. The incidence of osteonecrosis of the jaw in the general population is not known. Currently, there is insufficient evidence to confirm a causal link between low-dose BP use in the osteoporosis patient population and osteonecrosis of the jaw. Biphosphonates associated osteonecrosis of the jaw is associated with high-dose bisphosphonates therapy primarily in the oncology patient population.

Biphosphanates and Cancer
Cancer patients, mostly those with multiple myeloma and breast cancer whose disease has spread to their bones, generally take one of two biphosphonates, Zometa or the older Aredia, intravenously.

Biphosphanates and Osteoporosis
Osteoporosis patients usually take biphosphonates as pills, in much lower doses that patients with cancer. Those biphosphanate drugs — Fosamax, Actonel and Boniva — reduce the risk of fractures of the spine or hip, injuries that can create a steady downward spiral in patients' condition.