USC dentists link alendronate sodium to jaw necrosis

Researchers at the University of Southern California (USC) School of Dentistry recently released clinical data that links a common oral bisphosphonate to an increased incidence of jaw necrosis.

The study is among the first to acknowledge that even short-term use of common oral osteoporosis drugs may leave the jaw vulnerable to devastating necrosis, according to the report in the Jan. 1 issue of the Journal of the American Dental Association.

Fosamax (alendronate sodium, Merck) is the most widely prescribed oral bisphosphonate, ranking as the 21st most prescribed drug on the U.S. market since 2006, according to a 2007 report released by IMS Health.

Nine of 208 healthy School of Dentistry patients (4%) who take or have taken Fosamax for any length of time were diagnosed with osteonecrosis of the jaw (ONJ), even after researchers controlled for referral bias, said principal investigator Parish P. Sedghizadeh, DDS, MS, assistant professor of clinical dentistry at the USC School of Dentistry.

The study results are in contrast to drug makers’ prior assertions that bisphosphonate-related ONJ risk is only noticeable with intravenous use of the drugs, not oral usage, Sedghizadeh said in a press release.

“We've been told that the risk with oral bisphosphonates is negligible, but 4% is not negligible,” he said.

Most physicians who have prescribed bisphosphonates have not told patients about any oral health risks associated with the use of the drugs, even though short-term usage poses a risk due to the drug’s 10-year half-life in bone tissue, Sedghizadeh said in the press release.

Lydia Macwilliams of Los Angeles said no one told her about the risk posed by her 3 years of Fosamax usage until she became a patient of Sedghizadeh at the School of Dentistry.

“I was surprised,” she said in the press release. “My doctor who prescribed the Fosamax didn’t tell me about any possible problems with my teeth.”

Macwilliams was especially at risk for complications because she had three teeth extracted. The infection is a biofilm bacterial process, whereby the bacteria infecting the mouth and jaw tissues reside within a slimy matrix that protects the bacteria from many conventional antibiotic treatments. Bisphosphonate use could make the infection more aggressive in adhering to the jaw, Sedghizadeh said in the press release. The danger is especially pronounced with procedures that directly expose the jaw bone, such as tooth extractions and other oral surgery.

After her extractions, two of the three extraction sites had difficulty healing due to infection. “It took about a year to heal, but [they are] doing just fine now,” Macwilliams said in the press release.

Sedghizadeh hopes other researchers will confirm his findings and thus encourage more doctors and dentists to talk with patients about the oral health risks associated with the widely used drugs.

“Here at the USC School of Dentistry, we’re getting two or three new patients a week that have bisphosphonate-related ONJ, and I know we're not the only ones seeing it,” he said in the press release.

Reference:
Sedghizadeh PP, Stanley K, Caligiuri M, et al. Oral bisphosphonate use and the prevalence of osteonecrosis of the jaw: An institutional inquiry. J Am Dent Assoc. 140;1:61-66.