Oral and Intravenous Ibandronate in the Management of Postmenopausal Osteoporosis: A Comprehensive Review

Convenient strategies are needed for postmenopausal osteoporosis management. Current oral bisphosphonates are effective and generally well tolerated, but are hampered by strict dosing requirements. Less frequent dosing schedules are expected to improve adherence to therapy and hence outcomes. Ibandronate is a potent, nitrogen-containing bisphosphonate in ongoing clinical development exploring its potential to be administered less frequently than at weekly intervals. Uniquely, ibandronate can be administered either orally or as an intravenous (i.v.) injection, with a betweendose interval of >2 months. In postmenopausal women, oral ibandronate, when administered either daily or intermittently, has demonstrated robust antifracture efficacy at the spine (62% [p=0.0001] and 50% [p=0.0006] risk reduction versus placebo), accompanied by significant increases in bone mineral density (BMD) at the spine and hip, and suppression of bone turnover markers. Studies of intermittent i.v. ibandronate injections in postmenopausal women have shown doserelated BMD gains and bone turnover marker suppression comparable to those obtained after a similar duration of treatment with the proven effective oral ibandronate regimen. Furthermore, in a trial conducted in patients with corticosteroid-induced osteoporosis, intermittent i.v. ibandronate injections reduced vertebral fracture risk by 62% versus an active control (p=0.043). In all these trials, the oral and i.v. ibandronate regimens were well tolerated. Ongoing, large multinational clinical trials are investigating two intermittent ibandronate regimens: once-monthly oral and intermittent i.v. injections. These simple ibandronate regimens are expected to provide the optimal combination of efficacy, tolerability and patient convenience, leading to improved treatment adherence and thus, enhanced outcomes in postmenopausal osteoporosis.