[Risedronate]

Risedronate has recently been approved as a drug for osteoporosis treatment in Japan. According to its chemical structure, risedronate is designated a third generation bisphosphonate, which has potent anti-resorptive activity. Clinical studies conducted in Japan, North America and/or Europe revealed that risedronate reduces the risks of hip fractures and vertebral fractures by around 30% and around 50% compared with placebo over three years, respectively, and increases lumber spine BMD by around 5% at one year after starting treatment. In addition, risedronate produces a rapid and clinically important reduction in the risk of vertebral fracture and bone formed during risedronate treatment was histologically normal. Bone turnover markers, e.g., deoxypyridinoline, NTx, are reduced by around 40% (maximum). Although some bisphosphonates have been associated with upper gastrointestinal (GI) tract adverse events, a pooled analysis of 9 placebo-controlled clinical trials conducted outside Japan revealed no evidence that risedronate was associated with an increased frequency of adverse effects in the GI tract when compared with placebo.