Expert Panel Links Popular Bone Drugs to Rare Fracture

An expert panel concludes that bone-strengthening bisphosphonate drugs such as Actonel, Boniva and Fosamax can actually raise risks for a rare type of fracture of the thighbone. The panel is urging the U.S. Food and Drug Administration which has been awaiting the report to add a special warning to that effect on the drugs' labeling. "Bisphosphonates may be related to atypical femur fractures," said Dr. Elizabeth Shane, a professor of medicine at Columbia University's College of Physicians and Surgeons in New York City. She is the lead author of the report, which was compiled by a special task force at the American Society for Bone and Mineral Research.

"These fractures are very unusual," Shane added. "But we are still concerned that patients could still have these fractures. There may well be a link between these fractures and bisphosphonates." The FDA has been given a copy of the panel report for review, she said. The findings are published Sept. 14 in the Journal of Bone and Mineral Research. Bisphosphonates a class of prescription medications use to treat osteoporosis have been shown to lessen the odds of getting common bone fractures of the hip and leg. However, they may also help trigger a weakness that makes a particular type of thigh bone fracture more likely in rare cases, the panelists said.

There has been conflicting evidence on a such a link, however. For example, one study published in 2008 in the New England Journal of Medicine did find a correlation between the long-term use of Fosamax and atypical fractures in postmenopausal women. But a study published this March in the same journal seemed to refute the connection. The FDA had looked to the expert panel to help provide some clarity. The group's new recommendations came after a thorough review of 310 of these atypical thigh fractures. In that review, the panel found that 94 percent of these patients had taken bisphosphonates. Most had taken the drugs for five years or more. Shane noted these fractures are so unusual that they make up less than 1 percent of all hip and thigh fractures.