title: Efficacy and tolerability of once-weekly administration of 17.5 mg risedronate in Japanese patients with involutional osteoporosis: a comparison with 2.5-mg once-daily dosage regimen.
abstract: In this multicenter, randomized, double-blind controlled trial, the efficacy and safety of once-weekly dosing with 17.5 mg risedronate was compared with once-daily dosing with 2.5 mg risedronate in Japanese patients with involutional osteoporosis. A total of 496 patients were randomized to receive either once-weekly (n = 249) or once-daily (n = 247) treatment. All patients were supplemented with 200 mg/day calcium. Following 48 weeks of treatment, the mean (+/-SD) percent changes, from baseline, in the bone mineral density of the lumbar spine (L2-L4 BMD) in the once-weekly and once-daily treatment groups were 5.36 +/- 4.27% and 5.87 +/- 4.47%, respectively. The difference between the groups was -0.5% (95% confidence interval: -1.35% to 0.35%), demonstrating that the effect on BMD of once-weekly treatment was not inferior to that of once-daily treatment. The time-course reductions in biochemical markers of bone resorption (urinary N- and C-telopeptide of type I collagen) and bone formation (bone-specific alkaline phosphatase) were similar for the two dosing regimens. There were no differences in the incidence of new vertebral fractures or the worsening of existing fractures between the once-weekly (2.2%) and once-daily (2.7%) dosing regimens. No significant differences were observed between the two dosing regimens in the incidence or the type of adverse events. However, 10.1% of the patients in the once-daily group withdrew due to adverse events as compared to 5.2% in the once-weekly group. Moreover, drug-related adverse events, including upper gastrointestinal disorders and abnormal changes in laboratory parameters, tended to be less in the once-weekly dosing regimen than in the once-daily dosing regimen. In conclusion, once-weekly oral dosing with 17.5 mg risedronate was well tolerated in Japanese osteoporotic patients, and showed equivalent efficacy to once-daily oral dosing with 2.5 mg risedronate. This once-weekly regimen is expected to provide a more convenient therapeutic option as an alternative to daily dosing and to enhance patient compliance in long-term therapy for osteoporosis.
authors.affiliation: Department of Orthopedics, San-in Rosai Hospital, 1-8-1 Kaike-Shinden, Yonago, 683-0002, Japan. hide1215@aurora.ocn.ne.jp
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kishimoto
authors.forename: Masao
authors.initials: M
authors.lastname: Fukunaga
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kushida
authors.forename: Masataka
authors.initials: M
authors.lastname: Shiraki
authors.forename: Akira
authors.initials: A
authors.lastname: Itabashi
authors.forename: Hajime
authors.initials: H
authors.lastname: Nawata
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nakamura
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ohta
authors.forename: Kunio
authors.initials: K
authors.lastname: Takaoka
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohashi
mesh_terms: D000368:Aged; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D012968:Etidronic Acid / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy*; D000068296:Risedronic Acid
chemical_list: D050071:Bone Density Conservation Agents; D000068296:Risedronic Acid; D012968:Etidronic Acid