|Millions of American women take bisphosphonates, such as Fosamax and Reclast, to treat osteoporosis. (Associated Press/File 2005)|
Study affirms safety of drugs to aid bones
Long-term use does not raise risk of fracture
MILWAUKEE — A new study gives reassuring news about the safety of Fosamax and Reclast, bone-building drugs taken by millions of American women. It found that long-term use does not significantly raise the risk of a rare type of fracture near the hip.
On balance, these drugs prevent far more fractures than any they might cause when used to treat the bone-thinning disease osteoporosis, said the study’s leader, Dr. Dennis Black of the University of California, San Francisco.
“If we treated 1,000 osteoporotic women for three years, we estimate you would prevent 100 fractures,’’ at a possible cost of one or fewer of the unusual bone breaks examined in this study, he said. Results were published online yesterday by The New England Journal of Medicine.
Many older people, especially postmenopausal women, take these drugs, called bisphosphonates. They range in cost from $100 for a three-month supply of the generic version of
Studies show they lower the risk of spine and hip fractures, which can be debilitating and often lead to a downward spiral and death in the elderly.
The drugs are widely considered safe. But some case reports have tied them to unusual fractures of the upper thigh bone, just below the hip, that seem to occur without provocation or injury. Patients “just step, they hear a crack, and they suffer a fracture,’’ Black said.
To study this risk, researchers combined results from three large studies involving more than 14,000 women who were given Fosamax, Reclast, or dummy treatments for three to 10 years.
In all, 284 hip and leg fractures occurred, including 12 of the unusual upper-thigh type. There was a trend toward more of these unusual fractures among bisphosphonate users, but the difference was small enough to have occurred by chance. This is reassuring, although the study cannot rule out risk, Black said.
“There are too few fractures for definitive proof. But what it does show is that these are very, very rare,’’ he said.
Merck and Novartis sponsored the study. Several authors work for the companies, and some consult for them or other osteoporosis treatment makers.
Other reasons the study cannot completely rule out risk is that not many participants took the drugs longer than three years and many took a lower dose of Fosamax than is commonly used now, Dr. Elizabeth Shane of Columbia University writes in an editorial in the journal.
Still, the results show that “many more common and equally devastating hip fractures are prevented by bisphosphonates than are potentially caused by the drugs,’’ she concludes.