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 may 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.
Older people, especially postmenopausal women, take these drugs, called bisphosphonates. The costs range from $100 for a three-month supply of the generic version of Merck & Co. Inc.'s Fosamax pills to as much as $1,200 for an infusion every six months of Novartis AG's Reclast. Other brands are GlaxoSmithKline PLC's Boniva and Warner Chilcott PLC's Actonel.
In studies, they lowered the risk of spine and hip fractures, which often lead to a downward spiral and death.
While the drugs are widely considered safe, some case reports have tied them to unusual fractures of the upper thigh bone that seem to occur without provocation or injury.
In three large studies, 14,000 women were given Fosamax, Reclast or dummy treatments for three to 10 years. In all, 284 hip and leg fractures occurred, 12 of the unusual upper-thigh type. More of these unusual fractures were among users of the drugs, but the difference was small enough to have occurred by chance. This is reassuring, although the study cannot rule out risk, Black said.