Monday, April 23, 2007
While some patients go on hiatus from the medicine because they have improved in their bone density scores, some doctors advise a patient to pause bisphosphonates for the opposite reason – because progress has leveled off. Dr. Benjamin Lechner, a South Florida rheumatologist, says he has noticed that a number of his patients appear to plateau after several years on the medicine.
“When you stop resorption completely, you don’t get new bone formation either,” says Lechner, who serves as an associate professor on the University of Miami’s medical school voluntary faculty. The osteoblasts, cells which build bone, “won’t get the signal to do their thing – the processes are tied together.”
Lechner says another factor he considers when he advises a patient to discontinue bisphosphonate medication is the unknown effects of extended use. “We know they stay around in the body for a long time,” said Lechner, who may consider switching a patient to another type of drug, such as Forteo, an anabolic medication which works by stimulating the osteoblasts. “We don’t know about long-term side effects,” of bisphosphonates, he says.
One of bisphosphonate medications' most severe – although fortunately rare – side effects may be osteonecrosis of the jaw. Symptoms of this disease, which entails dead bone tissue, include toothache, loose teeth, jaw pain, recurrent infections in the soft tissue, and failure of the jaw to heal normally after an extraction or other procedure. However, the majority of bisphosphonate users who have suffered the problem are cancer patients who take higher (and often intravenous) doses of the drugs as compared to their osteoporosis counterparts.
New York-based Dr. Salvatore Ruggieri chaired the committee that established the guidelines for the American Association of Oral and Maxillofacial Surgeons on osteonecrosis of the jaw related to bisphosphonate use. While the incidence of such problems is very small – affecting less than one percent of oral bisphosphonate patients – it appears to be greater in those who have taken such medication for three or more years, or who use corticosteroids, such as those used to treat rheumatoid arthritis, consistently for a long period of time.
Despite the infrequency of problems, just to be safe Dr. Ruggieri recommends patients, in consultation with their treating physicians, consider stopping oral bisphosphonates for three to four months prior to dental procedures that require bone healing, such as placing implants or tooth extraction. After the surgery an oral surgeon should wait for evidence of normal bone healing before recommending the patient restart the medicine, he says.
“In as little as four months, the osteoclasts start to bounce back,” Ruggieri said. And for patients who have been taking the bisphosphonates for three or more years, “there is no risk of developing a fracture,” from such a brief holiday.
Ruggieri stressed that other routine procedures, such as periodontal cleaning and filling cavities, do not pose a risk of osteonecrosis since they do not involve the jawbone. And the American Dental Association stresses that bisphosphonate users can minimize potential problems with good oral hygiene and regular dental care.
