In one of the largest late-stage clinical programs ever conducted, the investigational pyridinyl bisphosphonate drug risedronate (Actonel) reduced the incidence of new vertebral fractures by up to 49 percent, and lowered the risk of osteoporosis related non-vertebral fractures by up to 39 percent. The results were presented at the annual meeting of the Endocrine Society.
Professor Richard Eastell, professor of bone metabolism at the University of Sheffield, UK, presented safety data from five clinical studies that enrolled a total of 5,226 post-menopausal women. The proportion of women reporting GI side effects was similar in the risedronate and placebo groups. Currently, risedronate is not available in Canada. For the full article see Nature 1999;397:315-23.