October 17, 2010

Osteoporosis Drug May Re-grow Jaw Bone

Forteo, a drug produced by Eli Lilly and Co. and used for osteoporosis, has been found to be able to re-grow bone in jaws damaged by severe bone-destroying conditions called osteonecrosis and periodontitis, doctors reported on Saturday.

The research suggests that the drug may drive growth in a damaged jaw, according to researchers.

Forteo, known as teriparatide generically, cuts the risk of bone fractures by half in patients with thinning bones by stimulating the growth of new bone. But the drug is seldom given for more than two years due to fear that long periods of exposure could lead to osteosarcoma, a cancer of the bone.

The first of two reports, published in the New England Journal of Medicine, showed that people whose severe periodontitis was damaging tissue around the teeth developed nearly ten times more bone with Forteo compared to those who received placebo injections.

Dr. Laurie McCauley of the University of Michigan found that Forteo caused "a significant gain in the bone around the teeth," as measured by X-rays. "This relatively short dosing period of six weeks resulted in improvements that were sustained, and things actually improved over 12 months."

McCauley said: "we were very pleased with these results and we're looking at other approaches."

"One is trying to administer the drug locally. We're also looking at the use of teriparatide in conjunction with dental implant therapy. There are situations where patients need to augment their bone to be able to have an implant. We think this could be a promising avenue for that," she said.

The other study, also reported in the Journal, involved a single 88-year-old woman whose jaw began to erode after a tooth was removed -- a condition known as osteonecrosis. Conventional treatment didn't help and the pain she experienced with the disease had persisted for a year.

Doctors had believed the problem may have been the woman's 10-year use of alendronate -- commonly known as Fosamax -- following a hip fracture. While Forteo spurs re-growth of new bone, Fosamax slows the normal absorption of exiting bone.

After 2 months of Forteo injections, the woman's pain disappeared and CT scans showed that bone cells had rebuilt that portion of the jaw.

Osteonecrosis often comes from radiation therapy for head and neck cancer. Periodontal disease, cancer, chemotherapy, glucocorticoid therapy, or trauma can also cause it.

Recently, however, high-dose intravenous bisphosphonates have been identified as a risk factor for osteonecrosis of the jaw among oncology patients.

Coauthor of the study, Dr. Ego Seeman of the University of Melbourne in Australia, said in a telephone interview that Forteo may be a candidate for counteracting the problem. But, such cases are so rare, one researcher cautioned it might be difficult to do a proper test to prove the treatment is effective.


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