Zoledronate once-yearly increases bone mineral density--implications for osteoporosis.

Osteoporosis is a major and growing problem for older women and men in western society. The bisphosphonates are used to treat postmenopausal osteoporosis because they decrease the risk of fractures. Oral bisphosphonates may cause oesophageal irritation and injury and are poorly absorbed. Intermittent intravenous bisphosphonates, including zoledronate, may be a way to avoid the problems associated with oral administration. Intravenous zoledronate increased bone mineral density while decreasing bone turnover and formation. Interestingly, the effects of a single dose (4 mg) of zoledronate were maintained over a year and were similar to those of three-monthly dosing with 0.25 - 1 mg zoledronate. If the increases in bone mineral density with zoledronate translate into reduced fractures, once-yearly intravenous zoledronate could be simple prophylaxis for postmenopausal osteoporosis.