Pharmacological management of severe postmenopausal osteoporosis

The most devastating consequence of osteoporosis is bone fracture, particularly at the vertebral or femoral level. As defined by the WHO, patients with osteoporosis who have had one or more fragility fractures have severe osteoporosis. Those who sustain a vertebral fracture represent a particularly vulnerable group whose risk of another vertebral fracture within the following year is increased by a factor of 3-5. In addition, the presence of a vertebral fracture is associated with an increased risk of hip fracture. In light of these data, treatment of established osteoporosis is extremely important to prevent other fragility fractures. This review examines the therapies approved by the US FDA for the treatment of osteoporosis that have been shown to reduce the incidence of new fractures in patients with established osteoporosis. We evaluated the mechanisms of action, available formulations, efficacy in preventing fractures and increasing bone mineral density (BMD), duration of treatment, adverse effects and contraindications to use of alendronic acid (alendronate), risedronic acid (risedronate), calcitonin, raloxifene and teriparatide. All these drugs are able to prevent new vertebral fractures in patients with established osteoporosis. Only alendronic acid and risedronic acid have also been shown to reduce the risk of fracture at the femoral level, but they are contraindicated in patients with upper gastrointestinal diseases. Calcitonin is a good option in subjects with back pain because of its analgesic effect. Raloxifene is useful when patients have high plasma lipid levels or a family history of breast cancer. Teriparatide is indicated in subjects with very low BMD and multiple vertebral fractures. Patient characteristics should determine selection of therapy but the decision is always difficult and fraught with uncertainty.