Risedronate Acts Quickly to Reduce Fracture Risk.

Patients who had the highest fracture risk were most likely to benefit from treatment.

SAN ANTONIO -- Five studies involving more than 13,500 patients now verify that the bisphosphonate risedronate quickly reduces fracture risk in patients with osteoporosis and in those taking glucocorticoids.

An analysis of data from the five studies presented at the annual meeting of the American Association of Clinical Endocrinologists, found that patients taking 5 mg/day risedronate (Actonel) were 40%-74% less likely to have a fracture than were patients assigned to placebo during the first year of the randomized trials.

Patients at the highest risk of fractures, including those with osteoporosis and at least two prevalent vertebral fractures, were most likely to benefit, with highly significant reductions in fracture risk of 67%-74%.

But the data also made it clear that traditional risk factors for fracture were not very predictive in very elderly women.

A subgroup of 3,886 women 80 years old and older did not experience a significant reduction in fractures if they were enrolled because they fulfilled "classic" risk factors, such as a maternal history of hip fracture, previous fall-related injuries in the past year, poor performance on tests of large motor skills, or a recent history of smoking, said Dr. Michael Bolognese, a specialist in diabetes, endocrinology, and internal medicine at the Bone Health Center in Gaithersburg, Md.

"You need to measure bone mineral density if you're going to treat people over 80," he said in an interview at the meeting. "Risk factors weren't enough," he added.