Biological properties and mechanism of action of ibandronate: Application to the treatment of osteoporosis

Bisphosphonates, with their proven efficacy and safety, are the most commonly prescribed treatment for women with postmenopausal osteoporosis; however, optimal efficacy is often not achieved due to poor patient adherence to medication. Poor adherence leads to an increased risk of fracture, which itself results in morbidity, elevated healthcare costs and potentially, mortality. Although weekly rather than daily dosing of bisphosphonates has improved adherence, there remains a significant problem, and dosing less frequently than weekly has been suggested as a possible means for further improving adherence. Ibandronate is a new bisphosphonate that has a specific structure and set of characteristics that enable less frequent dosing than currently available bisphosphonates. This review provides details of the general structural features of all bisphosphonates and how these are understood to contribute to their functions in osteoporosis treatment. From this, the unique structure of ibandronate is described, along with how this translates into the high antiresorptive potency, favorable bone-binding, persistence in bone, and good tolerability that permits less frequent dosing. Finally, the clinical evidence for ibandronate is briefly presented, demonstrating the viability of less frequent dosing, with its potential benefits for patient convenience and adherence to therapy.