Chapter 22. Anti-Osteoporosis Agents

Publisher Summary Although significant progress has been made in both prevention and treatment of osteoporosis, it remains a major health concern of increasing magnitude for several reasons, such as an aging population, improved diagnostic procedures, and increasing public awareness. Osteoporosis is a disease characterized by low bone mass and enhanced bone fragility, resulting in an increased risk of fractures. It results from a deficit in new bone formation versus resorption during the ongoing remodeling process. The objective of anti-osteoporosis therapy is to maintain or increase bone mass and bone strength, thereby reducing the risk of fractures. Anti-osteoporosis therapy falls into two classes; anti-resorptive and bone restorative (or anabolic) agents. Anti-resorptive therapy targets bone resorption, reducing bone turnover, and thereby preventing bone loss. It has been the major focus and current therapies fall into this class. More recently, the focus has shifted onto bone restoration. Bone restoration therapy when approved would seek to restore bone to osteopenic skeletons, thereby reducing the likelihood of skeletal fracture. Anti-resorptive therapy is preventative, while bone restoration is the treatment of osteoporosis. As more emphasis is placed on the treatment of osteoporosis, restoration of lost bone, it is not sufficient just to increase bone mass; to reduce the rate of fractures the new bone must be biomechanically sound.