Risedronate: A new oral bisphosphonate

Background. Bisphosphonates have been effective in the treatment of osteopo rosis and Paget's disease of bone. Risedronate, the newest oral bisphosphon ate, is approved by the US Food and Drug Administration for the prevention and treatment of postmenopausal osteoporosis and glucocorticoid-induced ost eoporosis and the treatment of Paget's disease of bone. Objective: This article reviews current studies of risedronate in osteoporo sis and Paget's disease of bone and, to the extent possible, compares rised ronate with other bisphosphonates and other therapies. Information on the p harmacokinetics and adverse effects of risedronate, and the drug's use in o ther disorders, is also reviewed. Methods: Clinical studies and review articles concerning the use of risedro nate published in the English-language literature from 1966 through October 2000 were identified through searches of MEDLINE, PREMEDLINE, and Internat ional Pharmaceutical Abstracts using the search terms risedronate and NE 58 095. Recent clinical studies, review articles, and consensus statements reg arding the use of other bisphosphonates were identified through searches of the same databases for this period using the search terms bisphosphonates, alendronate, osteoporosis, and Paget's disease of bone. Results: The use of risedronate therapy in patients with postmenopausal ost eoporosis has been shown to increase bone mineral density (BMD) and decreas e the incidence of fractures compared with placebo. In glucocorticoid-induc ed osteoporosis, risedronate has been shown to increase BMD without having a consistently significant effect on the risk of fractures. Although there are no direct comparisons between bisphosphonates in glucocorticoid-induced osteoporosis, rised-ronate appears to be less effective than alendronate a nd more effective than etidronate in terms of effects on BMD and/or fractur e risk. In Paget's disease of bone, risedronate has been reported to be mor e effective than etidronate in decreasing serum alkaline phosphatase levels and bone pain. Finally, risedronate has been associated with a lower incid ence of gastric ulcers than alendronate. Conclusions: In terms of efficacy in the prevention and treatment of osteop orosis and the treatment of Paget's disease of bone, risedronate is compara ble to alendronate, the other orally available bisphosphonate. It appears t o have better gastrointestinal tolerability than alendronate and may be pre ferred for patients in whom this is a concern. However, direct comparative and pharmacoeconomic studies are necessary to determine risedronate's relat ive place in the therapy of osteoporosis and Paget's disease of bone.