Injectable bisphosphonates for the treatment of osteoporosis.

Bisphosphonates are the current mainstay of the management of osteoporosis worldwide. Oral daily and weekly formulations have been linked to poor adherence, yielding a decrease in antifracture efficacy, in real-life settings. Development of new bisphosphonates, with increased antiosteoclastic potency and affinity for bone matrix allowed intravenous administration and intervals between dosings to be higher than weekly. Ibandronate and zoledronic acid have been investigated in established osteoporosis. Quarterly injections of ibandronate (3 mg) have been shown to be at least as effective in increasing bone mineral density and reducing bone turnover markers as the oral ibandronate regimen, which has proven antifracture efficacy. A once-yearly infusion of zoledronic acid (5 mg) during a 3-year period significantly reduced the risk of vertebral, hip and other fractures. Intravenous administration of bisphosphonates can now be considered as an important component of the management of postmenopausal osteoporosis.