Some existing drugs, effective in preventing spinal fractures, have not been as effective in curbing other bone fractures caused by osteoporosis, the bone-weakening condition that afflicts an estimated 10 million Americans.
Researchers say the new drug, risedronate, reduced other fractures as well as spinal fractures and increased bone density. Their study appears in this week's Journal of the American Medical Association.
The study's lead author said the findings should be heartening for older women who can't tolerate or aren't given after menopause estrogen treatments, still considered key to preventing or slowing the effects of osteoporosis.
"The prevailing feeling is that once you're old and starting to have problems, there's not much you can do," said Dr. Steven T. Harris, chief of the Osteoporosis Clinic at the University of California at San Francisco. "But I think this gives a lot of encouragement."
The study was funded by Proctor & Gamble Pharmaceuticals and Hoechst Marion Rousell, which are seeking approval from the Food and Drug Administration to sell risedronate under the trade name Actonel.
The three-year study of 939 postmenopausal women found that the number of nonspinal fractures dropped 39 percent for women who took the drug; spinal fractures decreased 41 percent.
The drug also boosted bone density by as much as 5 percent.
Another osteoporosis drug, alendronate, marketed as Fosamax, has had similar results when it comes to fractures and bone density increase.
Two other drugs have shown comparable results for spinal fractures but not for others, Harris said. Those include calcitonin, marketed as Calcimar, and raloxifene, marketed as Evista, recently approved by the FDA as an osteoporosis treatment.
Another osteoporosis expert, Dr. Lawrence Raisz, head of the general clinical research center at the University of Connecticut, said he was not surprised by the study's finding. But he said it is still unclear whether women experience less stomach upset with risedronate than they do with alendronate.