Teriparatide in the management of osteoporosis

Abstract

Fracture of the hip is frequently a catastrophic event in the elderly, often resulting in death within a year and of the survivors, few regain pre-fracture quality of life. Although less appreciated, fractures of the spine result in significant morbidity and are also associated with increased mortality compared with individuals without a fracture. In recent years there has been an explosion in the development of new drugs for the treatment of osteoporosis. Recombinant human parathyroid hormone (1-34) (20 microg/day) is a recent addition to this armamentarium with a novel mechanism of action, which was approved by the US FDA for the treatment of postmenopausal osteoporosis and male osteoporosis secondary to hypogonadism in November 2002. It is the first osteoporosis treatment that leads to the formation of new bone with architecture similar to normal bone. Intense efforts have been made to understand the effect of teriparatide on antiresorptive therapy and vice versa. Although these relationships are not completely understood, the results of recent studies allow clinicians to begin to optimize therapeutic gains in bone mineral density and improve anti-fracture efficacy.

Figure 1

Teriparatide therapy improves skeletal architecture. Micro-CT scans of iliac crest biopsy specimens at baseline (A) and after 21 months of therapy (B) with teriparatide (20 μg/d). Reproduced with permission from Jiang Y, Zhao JJ, Mitlak BH et al 2003. Recombinant human parathyroid hormone (1–34) [teriparatide] improves both cortical and cancellous bone structure. J Bone Miner Res, 18:1932–41. Copyright © 2003 American Society for Bone and Mineral Research.

Figure 2

Effect of teriparitide treatment (20 μg/d, black bar) compared with placebo (gey bar) on A. Risk of one or more new vertebral fracture. B. Risk of one or more new moderate or severe vertebral fractures.