December 15, 2011 — New guidelines from the American Dental Association (ADA) Council on Scientific Affairs steer dental professionals away from the perception that intravenous bisphosphonates are more likely to cause osteonecrosis of the jaw than oral ones.
The new guidelines, entitled "Managing the Care of Patients Receiving Antiresorptive Therapy for Prevention and Treatment of Osteoporosis," are posted on the ADA's Web site, and a summary appears in the November issue of the Journal of the American Dental Association.
The authors use the term "antiresorptive therapy" instead of "bisphosphonates" because at least 1 case of osteonecrosis of the jaw has been associated with a new drug for osteoporosis, denosumab, which is not a bisphosphonate. Other antiresorptive drugs might have similar effects.
Previous research led to the notion that dentists could safely treat patients taking oral bisphosphonates, but not those taking intravenous bisphosphonates.
That's an oversimplification, lead author John W. Hellstein, DDS, MS, told Medscape Medical News.
Dr. Hellstein, clinical professor of oral pathology, radiology, and medicine at the University of Iowa, Iowa City, explained that it is how often the drug is given and how close together, not whether it is given as an intravenous or oral dose. "What we have found over the years is that a dose–response curve is becoming very evident."
Cancer patients might take a much higher dose than osteoporosis patients, he pointed out. For example, zoledronic acid used for intravenous cancer therapy is given in doses of about 48 mg/year, whereas for osteoporosis and metabolic bone disease, it is given in doses of approximately 5 mg/year.
However, the guidelines do not give precise standards for how much of the antiresorptive agents patients can safely take.
The guidelines also point out that there is no test yet to determine which patients are most likely to suffer from osteonecrosis.
Patients who don't have cancer run only a low risk of developing osteonecrosis, the guidelines say; the highest published estimated of prevalence in a large sample of patients is about 0.10%.
Among the risk factors are being older than 65 years, periodontitis, prolonged use of bisphosphonates (for more than 2 years), smoking, wearing dentures, and diabetes.
Clinicians should ask their patients whether they use any antiresorptive drugs, and if they do, should inform them of the small risk with dentistry. But in general, they should not advise their patients to stop the antiresorptive therapy, the guidelines say.
"There is nothing convincing in the literature to recommend a drug holiday," said Dr. Hellstein.
Clinicians can then proceed slowly and cautiously. For example, a sextant of the person's mouth can be treated and observed before going on to tackle the rest.
"If they heal well in one corner of the mouth, they are likely to heal well in another corner of the mouth," said Dr. Hellstein.
The new guidelines won praise from Jeffrey Fellows, PhD, an investigator at the Kaiser Permanente Center for Health Research and lead author of a recent study on osteonecrosis of the jaw published in Clinical Medicine and Research.
"I think that they are all good recommendations," Dr. Fellows, who did not serve on the ADA committee, told Medscape Medical News.
That recent study, which looked retrospectively at 2 matched sets of dental and medical charts, confirmed that the risk for osteonecrosis of the jaw with bisphosphonates is small.
But it found that patients were very concerned about the risk, and often wanted to stop using bisphosphonates when they needed dentistry. Providers were well informed of the limited risk, the study found.
"Patients and medical providers really need to talk to each other," said Dr. Fellows. "That was the most salient part of the recommendations, in my reading."
Dr. Hellstein reports being paid to testify as an expert witness on behalf of plaintiffs in bisphosphonate lawsuits and to review records related to the lawsuits. Dr. Fellows has disclosed no relevant financial relationships.
J Am Dental Assoc. 2011;142;1243-1251. Abstract
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Cite this: American Dental Association Updates Osteonecrosis Guidelines - Medscape - Dec 15, 2011.