FDA Panel: Osteoporosis Drugs Need Better Labels
Time Limits on the Drugs Are Suggested, but How Much Time Is Yet to Be Determined
Long-Term Use of Bisphosphonates
Panelists noted that it's difficult to predict which women will benefit from long-term bisphosphonate use. The Fosamax study did find that women's bone mineral density at the time they discontinued the drug was strongly related to their fracture risk over the next five years, Bauer told panel members.
The findings probably can be generalized to weekly dosing of Fosamax, he said, but it's unclear how they relate to other bisphosphonates.
Paul Miller, MD, medical director of the Colorado Center for Bone Research, noted that long-term use wasn't an issue when bisphosphonates first came on the market. At that time, "we didn't treat a lot of women in their 50s or early 60s with bisphosphonates," said Miller, who was representing Warner Chilcott, maker of Actonel. "We treated sicker women in their 70s and 80s."
In July 2002, the first published results from the Women's Health Initiative changed all that, he said. The study found that Premarin, the top-selling brand of postmenopausal estrogen, increased heart attack, stroke, and breast cancer risk. Postmenopausal women who had been on hormone therapy to protect their bones flooded doctors' offices in search of an alternative, Miller said.
Most of the bisphosphonate patients who testified before the panel about their unusual thigh fractures said they had started taking the drugs in their 50s or 60s. Some of the women said they'd been prescribed the drugs for osteopenia, which means their bone mineral density was lower than normal but not low enough to be classified as osteoporosis.
Advisory committee member Clifford Rosen, MD, director of the Center for Clinical and translational Research at the Maine Medical Center Research Institute in Scarborough, questioned the wisdom of prescribing bisphosphonates simply to prevent osteoporosis, as opposed to treating it.
"A prevention indication, I think, is being revisited all the way around, including by the FDA," Kehoe said in response. "Certainly it's something we're struggling with and dealing with."