There have long been safety questions — and lawsuits — over whether bone-building drugs like Merck’s Fosamax can actually increase the chance of femur fractures. Today, the FDA said it was going to take another look at the safety issues.

In a posting on its Web site, the FDA said a 2008 examination of data from makers of osteoporosis drugs containing bisphosphonates didn’t show that women taking the medications had an increased risk of fracturing their femurs — the bone just below the hip joint.

But studies released today at the annual meeting of the American Academy of Orthopaedic Surgeons raised new questions about the risks for long-term use of bisphosphonates by post-menopausal women. USA Today has more.

In its latest review, the FDA said it would work with outside experts on the matter. While that’s happening, people on the medications should continue taking them but should talk to their doctors if get any new hip or thigh pain, the agency said.

Bisphosphonates have combined annual sales topping $3.5 billion. In addition to Fosamax, drugs in the group includes Actonel marketed by Sanofi-Aventis and Procter & Gamble, Boniva marketed by Roche and GlaxoSmithKline, Novartis’s Reclast and P&G’s Actonel. Reuters and Dow Jones Newswires have more details.

Merck is defending itself against more than 900 product-liability lawsuits by patients mostly claiming Fosamax caused death of their jaw-bone tissue. The FDA more recently has held up approval of other drugs in the bone-treatment pipeline as the agency has sorted through a variety of safety concerns.

Reported by James A. White