Selection of antiresorptive or anabolic treatments for postmenopausal osteoporosis

Osteoporosis is a common, chronic disease that can be treated effectively by pharmacological interventions. Antiosteoporotic drugs reduce fracture risk via different mechanisms of action. Available therapies are broadly distinguished into inhibitors of bone turnover, stimulators of bone formation, and therapies with as-yet unclear mechanisms of action. No direct comparison studies with fracture end points have yet been done, which makes selection of one drug over another difficult. Identification of individuals who might derive particular benefit from a specific therapy has been explored in post-hoc analyses of clinical studies with bisphosphonates and recombinant parathyroid hormone (PTH). Their findings showed that the efficacy of these therapies in reducing fracture risk was largely independent of the prevalent rates of bone turnover. Selection of a specific antiosteoporotic therapy should, therefore, be made according to the results of trials specifically designed to assess fracture risk, safety, tolerability, patient preference and cost-effectiveness rather than on characteristics specific to patients or the disease. Studies of sequential administration of PTH and bisphosphonates suggest advantages over single-therapy regimens, particularly in patients with severe disease. However, the optimum duration of PTH administration, as well as the efficacy of such regimens in reducing the risk of fractures, remain to be determined.