Fosamax risk weighed
A few cases link drugs for osteoporosis to jawbone diseaseJun 19, 2006 | www.telegram.com Graphic designer Patricia Korch settled into her oral surgeon’s chair, ready to have a troublesome tooth extracted as part of orthodontia she’d delayed for many years.
“You take Fosamax,” he said, studying her medical history form.
“Yes, I do,” she replied.
He walked around the chair, as if he was going to break bad news to her, she recalled.
Then he did.
He told her that Fosamax, which she took to stave off the bone-weakening disease osteoporosis, was one of a class of drugs called bisphosphonates implicated in a serious bone disease. In a small number of cases, after tooth extraction or implant placement, the bone failed to heal, remained exposed or became infected.
Called osteonecrosis of the jaw, or ONJ, it was first linked to bisphosphonates by a Miami dentist in 2003. No cases were reported in any of the clinical trials done before the drugs went on the market, but Dr. Robert E. Marx noticed ONJ among 36 cancer patients who were taking intravenous versions of the drugs. The medications were prescribed to prevent fractures and ease pain caused by cancer that had spread to their bones.
Case reports continued to crop up, including 15 patients who were taking oral forms of the drug to prevent osteoporosis. A May article in the Annals of Internal Medicine reviewing previously published reports said 94 percent of patients who developed ONJ were being treated for metastatic cancer with IV bisphosphonates. Sixty percent of patients had a dental procedure done before ONJ was diagnosed.
The risk for people undergoing oral surgery while taking oral bisphosphonates, such as Fosamax, Boniva and Actonel, is unknown, the article’s authors said, but for people like Ms. Korch contemplating elective oral surgery, any risk was too high.
“It was very shocking,” she said. “You can’t really minimize it because there’s no cure for this.”
Her orthodontist and dentist devised a plan to perform a root canal, after which the tooth, no longer connected to the bone, will come out like a baby tooth. In that way the bone would not be affected and her orthodontia to correct severe crowding could continue.
That will solve her immediate problem, but she still decided to stop taking Fosamax.
Medical experts, including the National Institutes of Health, haven’t gone that far. The National Institute of Arthritis and Musculoskeletal and Skin Diseases calls cases linking these oral drugs to ONJ rare. Its Center for Clinical Research is planning research into the question.
The Food and Drug Administration has ordered the makers of bisphosphonates to list ONJ in its precautions on package inserts.
Dr. Meryl S. Leboff, director of the skeletal health and osteoporosis program at Brigham & Women’s Hospital in Boston, also calls the risk low.
“We really don’t know the true incidence of this problem worldwide, but the risk in patients who are treated with oral bisphosphonates is very, very low. Low, but not zero,” she said. “It’s important for physicians to work with dentists and oral surgeons and that patients really try to optimize their dental hygiene.”
Osteoporosis the disease the drugs target affects 10 million Americans, leading to fractures for one out of two women and one out of four men over 50 in this group, according to NIAMSD.
About 34 million Americans, both men and women, have low bone mass, putting them at risk for osteoporosis. Being older, female, Caucasian or Asian, and having a family history of osteoporosis puts people at higher risk. Other factors estrogen and testosterone levels, physical activity, diet, medications, alcohol, cigarettes also come into play.
Low bone mass occurs when the process of old bone being renewed (resorption) and new bone being formed (formation) changes. Up until about age 30, formation outpaces resorption. After that the ratio shifts. Bone loss can eventually lead to osteoporosis.
Bisphosphonates prevent bone loss by inhibiting resorption of old bone and interfering with the bone formation. Scientists theorize that ONJ may occur after oral surgery in patients taking bisphosphonates because the drugs thwart the bone resorption needed for healing. Another possible explanation is that the drugs prevent formation of new blood vessels, causing the bone tissue to die.
Whatever the mechanism, there is no cure for ONJ. And bisphosphonates do stay in the body for years after a person stops taking them. In a position paper published last year, the American Academy of Oral Medicine said prevention was the best approach.
“The message needs to be that anyone considering Fosamax should really get their dentistry straightened out because of the risk of osteonecrosis,” said Dr. Stanley M. Levenson of Worcester, who is Ms. Korch’s dentist and agreed when her oral surgeon would not extract her impacted tooth. “She was lucky that wasn’t something she had to do.”
Some 23 million Americans take oral bisphosphonates for osteoporosis, according to the American Dental Association. And some of them need to have infected teeth extracted.
Dr. Shay Shen, a Worcester oral surgeon, said he looks at whether a patient is taking oral or intravenous bisphosphonates and at how high a dose.
“But if the tooth really needs to be removed and there’s no other way of doing it, we still go ahead and remove the tooth,” he said. “It’s not an absolute contraindication that you cannot take a tooth out if a patient is taking Fosamax.”
Patients are put on antibiotics to prevent infection after oral surgery.
Ms. Korch, who gives her age as “45-plus,” attributes her low bone mass to her small stature, European heritage and family history.
“I am in good health other than issues with bone density. If you had the option of the possibility of developing an irreversible, excruciatingly painful, disfiguring disease, would you take that chance?” she asked in a chat room on www.archwired.com, a site for adults wearing braces.
Dropping a medication is not new to her. She was on hormone replacement therapy until the Women’s Health Initiative clinical trial was halted in 2002 because of an increased risk of heart attacks and stroke that outweighed the benefit of bone strength. She said she is frustrated by the lack of information on Fosamax at this point, but plans to stay off the drug at least until her alternative to tooth extraction is completed.
“It’s everybody out of the pool again,” she said.