Once-monthly ibandronate.

Abstract

Ibandronate is a nitrogen-containing bisphosphonate that has been approved for once-monthly administration in women with post-menopausal osteoporosis. Animal data suggest that the efficacy of the drug is determined by the cumulative dose rather than the frequency of administration. After treatment for 1 year in a large, randomized, double-blind, multicenter trial in women with postmenopausal osteoporosis, once-monthly ibandronate 150 mg was non-inferior to once-daily ibandronate 2.5 mg in terms of increases in mean lumbar spine (primary endpoint) and hip bone mineral density (BMD). In addition, once-monthly ibandronate 150 mg was significantly more effective than once-daily ibandronate for mean increase from baseline in lumbar spine BMD after 1 and 2 years. In another large, randomized, double-blind trial in women with osteoporosis, both once-daily and intermittent (>2-month between-dose interval [not approved]) ibandronate were significantly more effective than placebo in reducing the risk of new vertebral fractures, after treatment for 3 years. Once-daily and intermittent ibandronate also increased mean lumbar spine and hip BMD from baseline by significantly more than placebo. Oral once-monthly, once-daily, and intermittent ibandronate were generally well tolerated. Monthly ibandronate had a similar tolerability profile to once-daily ibandronate. The incidence of adverse events, including gastrointestinal events, with once-daily and intermittent ibandronate did not differ significantly from that with placebo. Significantly more women with osteoporosis preferred once-monthly ibandronate and found it more convenient than once-weekly alendronate, according to data from a 6-month, randomized, open-label, crossover study.