Anabolic therapy for osteoporosis.
Antiresorptive agents for osteoporosis are a cornerstone of therapy, but anabolic drugs have recently increased our options. By directly stimulating bone formation, anabolic agents reduce fracture incidence by improving bone qualities as well as increasing bone mass. The anabolic agent currently approved for osteoporosis, teriparatide (recombinant human parathyroid hormone[1-34]), has emerged as a major approach for selected patients with osteoporosis. Parathyroid hormone(1-84) is also available in Europe. Teriparatide increases bone density and bone turnover, improves microarchitecture and changes bone size. The incidence of vertebral and nonvertebral fractures is reduced. A current concept in the mechanism of teriparatide action is related to its effect of stimulating processes associated with bone formation before processes associated with bone resorption. This sequence of events has led to the concept of the anabolic window, the period of time when teriparatide is maximally anabolic. Newer approaches to the use of teriparatide alone and in combination with antiresorptive agents has led to ways in which the anabolic window can be expanded.
Bilezikian
John P
JP
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 USA. jpb2@columbia.edu.