Oral bisphosphonates may lower jaw necrosis risk
NEW YORK (Reuters Health) - A report in the Journal of the American Dental Association clarifies the risk of jaw osteonecrosis associated with bisphosphonates, which are used to prevent or slow the progression of osteoporosis.
Intravenous bisphosphonates strongly increase the risk of adverse jaw outcomes, but oral bisphosphonates tend to decrease the risk, the research shows. Intravenous bisphosphonates are usually used to treat bone cancer or severe cases of osteoarthritis.
"This is good news for the roughly 3 million Americans who take Fosamax, Actonel, Boniva or similar osteoporosis meds orally," senior author Dr. Athanasios Zavras, from the Harvard School of Dental Medicine in Boston, said in a statement.
In 2003, reports first surfaced linking intravenous bisphosphonate treatment with osteonecrosis of the jaw. This is a serious condition in which bone tissue dies, resulting in the loss or destruction of the jawbone. Symptoms may include pain, swelling or infection of the gums and jaw, gums that don't heal, loose teeth and numbness of the jaw.
Oral versions of these agents were initially thought to be safe until a report came out in May 2005 showing that 7 of 63 bisphosphonate users who developed the condition had been using oral forms.
To investigate further, the researchers analyzed medical claims from 714,217 patients with osteoporosis or cancer to determine the effect that bisphosphonate use had on the risk of three outcomes: inflammatory conditions of the jaw (including osteonecrosis), major jaw surgery because of necrosis (tissue death), or jaw surgery for a malignancy.
The results showed that intravenous bisphosphonate use increased the risk of inflammatory necrosis of the jaw by 4.0-fold in patients with osteoporosis and by 4.5-fold in those with cancer. Among patients with either condition who required surgery for necrosis, the risk increased by 7.8-fold and 6.8-fold, respectively. No significant increase in risk was associated with surgery for cancer.
By contrast, oral bisphosphonate use reduced the risk of inflammatory necrosis of the jaw by 35 percent in patients with osteoporosis. No significant effects of oral bisphosphonates were associated with surgery for necrosis in this patient group or for any of the adverse jaw outcomes in cancer patients.
"Our findings on intravenous bisphosphonates are consistent with the literature, which makes me confident that our findings on oral bisphosphonates are correct," Zavras stated. "We're currently recruiting patients for a clinical study to confirm them."
SOURCE: Journal of the American Dental Association, January 2008.
