It's not as good as young bones.

Two new studies found some bones of postmenopausal women who take bisphosphonates (Actonel, Боніва, Fosamax, Reclast), to display

can stop rejuvenating and become brittle after extended use. "It is a paradox," says Melvin Rosenwasser, director of orthopedic trauma surgery

New York. "These drugs are good drugs. They strengthen bones and protect you from fractures for a while. But in some people they can become harmful after a certain period of time. "

Food and Drug Administration is studying the issue of long-term use of bisphosphonates, but did not see the new research, said spokeswoman Ellen Bobo. Osteoporosis is a major threat to the health of an aging population. An estimated 10 million Americans have the disease and almost 34 million have low bone mass, they are at risk for spine and hip fracture. Women are more likely to suffer from it than men. Bisphosphonates are among the best selling drugs in the U.S., according to data research company that tracks prescriptions. Annual sales exceed $ 3. 5000000000 dollars. Drugs effective in slowing bone loss at first, says Joseph Lane, chief of metabolic bone disease in hospital special surgery in New York. The study will present today at the annual conference of the American Academy of orthopedic surgeons lasix generic side effects in New Orleans, was designed to investigate why one of the 50 women who received fractures and were on drugs for more than five years suffered atypical hip fractures of the femur. "This is a healthy active women, not women in nursing homes," says Lane. "Hip fractures can be life threatening, so we want to find out what causes them into prosperous women."

Study of bone biopsies in women who suffered hip fractures, Lane found a decreased bone quality after prolonged use of bisphosphonates. "Usually bone distribution of young bone, middle age bone and old bone," he says. "When we look at these bones, this old bone. You begin to start with defects in bone. It's not as good as young bones. " Research

Rosenwasser, also presented at the conference indicated that bone densitometry (DXA) scan shows the bending potential in the hip joint arthroplasty in patients receiving treatment for osteoporosis bisphosphonates. His research note fall after four years use or more. "It can be seen as fragile," Rosenwasser said. "Think of it as not in need of bone, but the quality of the organization."

He said that more research is needed. Merck Representative Ron Rogers said that the company has updated Fosamax tags contain information about the "side effects".

"The reason for communication" has not been established between long-term use of bisphosphonates and these atypical fractures, he said. "In our clinical trials with Fosamax, there was no increased risk of fractures of the skeleton at any site."

Terry Hurley, spokesman, said that "safety and effectiveness" bonds, have been shown in large clinical trials. "We take patient safety seriously," he says, "and we will work closely with the FDA, to better understand the reports of these fractures."