In a separate report Thursday in the Journal of the American Dental Assn., Parish Sedghizadeh of the USC School of Dentistry reported that he had observed nine cases of osteonecrosis of the jaw among 208 patients taking oral bisphosphonates — an unusually high incidence.
Osteonecrosis of the jaw — death of the bone — is known to occur in 1% to 10% of cancer patients taking intravenous bisphosphonates to combat bone weakening brought on by chemotherapy. It is rarely observed in patients taking oral forms of the drug, however.
Some people immediately dismissed his findings, arguing that the widespread use of the drugs would have already revealed such a high incidence of a disabling side effect.
“The most important criticism is that the sample size was only 208 patients,” said Dr. Robert R. Recker, director of the Osteoporosis Research Center at Creighton University in Omaha and president of the National Osteoporosis Foundation. “The study design and sample size were simply inadequate to make any conclusions.”
Both the American Society for Bone and Mineral Research and the American Dental Assn. have recently conducted comprehensive reviews of the risks of osteonecrosis associated with oral bisphosphonates, added Dennis Black, a professor of epidemiology and biostatistics at UC San Francisco. They concluded “that the risk is somewhere between 1 in 10,000 and 1 in 100,000, and it is not clear that this is increased by bisphosphonates,” he said.
The American Dental Association today issued the following advisory which is here.
Most noteworthy from the advisory:
- The American Dental Association has reviewed previous studies on this issue which indicate that use of oral bisphosphonates (medication commonly prescribed for patients with osteoporosis) has been associated with a low risk for developing ONJ-one study indicated 1 out of 2,260 people taking oral bisphosphonates develop ONJ. This new study from USC claims that the frequency of ONJ among oral bisphosphate users is higher than previously reported-approximately 4 percent of the people studied.
- It’s important for me to know if you are on bisphosphonate drugs or if you’ve used them in the past because of the possible risk of developing ONJ. ONJ is uncommon, but it can be serious. If you have received bisphosphonate therapy intravenously related to cancer therapy, you may be at a higher risk of developing ONJ than if you take oral medication.
- Current ADA recommendations suggest that routine dental treatment generally need not be altered merely because a patient is taking or has taken oral bisphosphonates. However, patients with any history of bisphosphonate therapy should be especially encouraged to practice optimal oral hygiene and to receive routine dental examinations. Furthermore, a comprehensive oral examination and treatment before or soon after commencing bisphosphonates therapy may be beneficial for patients if they’re not already receiving regular dental care to treat existing oral health problems
A previously issued patient handout is available for download here (pdf).
This is a controversy which will be further studied.
In the meantime, Flap urges caution for patients taking ORAL Bisphosphonate medications. And,please patients update your health history and tell your dentist if you are using these drugs.