Osteonecrosis warning
Cancer drugs preclude some dental procedures
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Posted May 12, 2005 |
By Mark Berthold East Hanover, N.J. — Cancer patients treated with intravenous bisphosphonate drugs may be at increased risk for developing "osteonecrosis of the jaw" — and they should not undergo invasive dental procedures, advises a pharmaceutical manufacturer.
Novartis Pharmaceuticals Corp. is sending a letter to dentists across the country, informing them that ONJ has been observed in cancer patients who are receiving Aredia or Zometa — bisphosphonates used to treat complications of advanced cancer known as "hypercalcemia of malignancy."
Novartis recommends that cancer patients receive a dental examination prior to initiating therapy with Aredia or Zometa, and avoid invasive dental procedures while receiving these drugs because dental surgery may exacerbate the ONJ condition. It has added precautionary information on ONJ to the package insert for both products.
Novartis also encourages dentists to report any serious adverse events related to Aredia or Zometa to its toll-free number, 1-800-882-6577, or to the Food and Drug Administration's MedWatch Adverse Event Reporting program, by phone at 1-800-FDA-1088 or online at www.fda.gov/MedWatch.
For more information, contact Novartis Oncology Medical Services at 1-888-669-6682.
Bisphosphonate use growing
Bisphosphonate drugs are fairly common in the United States: greater than 23 million Americans took the oral form in 2003 to treat osteoporosis and other conditions, according to Dr. John W. Hellstein, clinical professor of oral and maxillofacial pathology at the University of Iowa.
"Less than 10 percent of reported cases of 'osteonecrosis of the jaw' are related to oral bisphosphonates," he says, "so the risks associated are real — but so far rare."
On the other hand, Dr. Hellstein believes, infusible bisphosphonates have a much higher risk of ONJ — about 90 percent of reported cases. Infusible bisphosphonates are used to treat cancers such as metastatic breast cancer, prostate cancer and multiple myeloma.
Signs of ONJ include exposed bone; pain, swelling or infection of gums; loosening of teeth; poor healing of gums; numbness or feeling of heaviness in the jaw; and draining with sequestration.
Problems have occurred after a tooth extraction in dental patients who had received the drug up to a year prior. The extraction site becomes necrotic and affects the surrounding bone, so that part of the jaw eventually may have to be removed. Spontaneous exposure of tori or the internal oblique ridge have also been reported.
However, "currently there are no indications to stop taking oral bisphosphonate medications for osteoporosis, such as ibandronate, alendronate or risidronate," says Dr. Hellstein. "And we don't want cancer patients to stop taking their infusible bisphosphonate, such as pamidronate or zoledronate, for hypercalcemia of malignancy."
What Dr. Hellstein wants is for the dentist to be aware of the possible complications associated with periodontal disease, tooth extraction, exposed tori or dentoalveolar/perioral trauma, especially in patients having a history of being administered infusible bisphosphonates.
Thus, much more attention and reporting of complications associated with the oral bisphosphonates, he believes, will help delineate the risks associated with osteoporosis medications.
"Preventive dentistry and good oral health care are still the best tools to reduce risks due to these medications and reduce complications in these patients already medically at risk," he says.
Dr. Hellstein adds that conservative treatment modalities are being evaluated for patients who do experience ONJ and how to manage patients requiring tooth extractions or bone exposure.
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