Present and future pharmacotherapy for osteoporosis

Although neither calcium nor vitamin D has been shown to prevent osteoporosis in postmenopausal women alone, the combination does. Both calcium and vitamin D are commonly used in the treatment of osteoporosis. The estrogens and raloxifene both prevent bone loss in postmenopausal women, and the estrogens probably also decrease the risk of first fracture. There is good evidence that raloxifene prevents further fractures in postmenopausal women who have already had fractures and some evidence that estrogen does as well. Calcitonin increases bone mineral density in early postmenopausal women and men with idiopathic osteoporosis, and also reduces the risk of new fractures in osteoporotic women. The bisphosphonate alendronate prevents bone loss and reduces fractures in healthy and osteoporotic postmenopausal women, and in osteoporotic men. Risedronate is more potent and has fewer upper gastrointestinal side effects than alendronate, and reduces the incidence of fractures in osteoporotic women. Intermittent use of the potent bisphosphonate zoledronate also increases bone mineral density and may become an alternative in the prevention and treatment of osteoporosis. All of the agents discussed above prevent bone resorption, whereas teriparatide increases bone formation and is effective in the treatment of osteoporotic women and men. In the treatment of secondary osteoporosis associated with the use of glucocorticoids to treat inflammation or prevent rejection after transplantation, the bisphosphonates are effective. The agents that have undergone some clinical trialing as new or alternative drugs for the treatment of osteoporosis include tibolone, new SERMs, androgens, growth hormone, insulin-like growth factor-1 and stontium ranelate. The targets/drugs that are being developed to inhibit bone resorption include the OPG/RANKL/RANK system, cathepsin K inhibitors, vitronectin receptor antagonists, estren, the interleukin-6 and gp130 system, cytokines and growth factors. New drugs/targets to promote bone formation include the commonly used lipid-lowering statins and the calcilytic release of PTH. (C) 2003 Prous Science. All rights reserved.