Combination/sequential therapies for anabolic and antiresorptive skeletal agents for osteoporosis.

In this paper, we focus upon the use of anabolic skeletal therapy for the treatment of postmenopausal and other forms of osteoporosis. The only anabolic skeletal agent currently available is a recombinant bioactive fragment of parathyroid hormone, PTH(1-34), known as teriparatide. The full length molecule, human PTH(1-84) is being investigated at this time as are other PTH molecules. Teriparatide improves bone quality by actions on bone turnover, bone density, bone size, and microarchitecture. In postmenopausal women with osteoporosis, teriparatide reduces the incidence for vertebral and nonvertebral fractures. In individuals who have been treated previously with an antiresorptive agent, the subsequent actions of teriparatide on bone density are delayed transiently if bone turnover is markedly suppressed. Combination therapy with teriparatide or PTH(1-84) and an antiresorptive does not appear, at this time, to offer advantages over the use of PTH or an antiresorptive alone. To maintain the gains in bone density with PTH, it is important to follow its use with an antiresorptive agent.