Osteoanabolic Agents for Osteoporosis.

Medications for osteoporosis are classified as either antiresorptive or anabolic. Whereas antiresorptive agents prevent bone resorption, anabolic agents promote new bone formation. Anabolics should be considered in individuals with severe osteoporosis, failure of alternative osteoporosis agents, intolerability or contraindications to other osteoporosis agents, and glucocorticoid-induced osteoporosis. There are currently two approved anabolic therapies, teriparatide and abaloparatide, and a third anabolic agent, romozosumab, is under review by the US Food and Drug Administration. Teriparatide and abaloparatide are administered as daily subcutaneous injections and have been shown to reduce vertebral and nonvertebral fractures significantly. The most common side effects are headache and nausea, but teriparatide and abaloparatide are generally well tolerated. The sequence of administration of anabolic therapy is important. Benefits of anabolics are attenuated in individuals with prior antiresorptive exposure; however, antiresorptive agents administered after anabolics consolidate bone mineral density gains.