Indications for initiation of drug therapy and modern therapy protocols in patients with osteoporosis

Introduction. Pharmacotherapy and physical therapy in patients with osteoporosis are aimed at increasing bone density and reducing the risk of fall in order to prevent fractures. Medications approved for the treatment of osteoporosis reduce the risk of fracture, either by reducing bone resorption or by stimulating bone formation. Bisphosphonates are most widely used antiresorptive agents that lower bone turnover markers to premenopausal levels and reduce fracture rates. Bisphosphonates bind to bone minerals and have a long-lasting effect. Long-term, continuous use of oral bisphosphonates is usually interspersed with drug breaks of 1-2 years to reduce the risk of atypical femoral fractures. Denosumab is a monoclonal antibody that also acts as an antiresorptive and it targets receptor activators of nuclear factor-?B ligand thus inhibiting the formation and function of osteoclasts. Denosumab is administered as a subcutaneous injection every 6 months. Anti-fracture effects of denosumab are similar to those of bisphosphonates, but there is a marked loss of antiresorptive effect 7 months after the last dose, which may lead to recurrent vertebral fractures. Anabolic drugs work by stimulating bone formation. Teriparatide and abaloparatide bind to the parathyroid hormone-1 receptor and are given as daily subcutaneous injection for up to 2 years. Romosozumab is a monoclonal antibody that targets sclerostin, stimulates bone formation and inhibits resorption. The effects of anabolics are transient, so it is necessary to switch to antiresorptive medications. Conclusion. It is a matter of great importance to determine the optimal strategy for cycles of anabolics, antiresorptive drugs and therapy-free periods.