Antiresorptive Drugs Beyond Bisphosphonates and Selective Oestrogen Receptor Modulators for the Management of Postmenopausal Osteoporosis

Osteoporotic fractures are a major cause of morbidity in the elderly population. Since postmenopausal osteoporosis is related to an increase in osteoclastic activity at the time of menopause, inhibitors of bone resorption have genuinely been considered an adequate strategy for prevention and treatment of osteoporosis. Bisphosphonates and selective oestrogen receptor modulators are widely prescribed to treat osteoporosis. However, other antiresorptive drugs have been developed for the management of osteoporosis, with the objective of providing a substantial reduction in osteoporotic fractures at all skeletal sites, combined with an acceptable long-term skeletal and systemic safety profile. Denosumab, a human monoclonal antibody to receptor activator for nuclear factor kappa B ligand, has shown efficacy against vertebral, nonvertebral and hip fractures. Its administration every 6 months as a subcutaneous formulation might significantly influence compliance and persistence to therapy. Additional results regarding long-term skeletal safety (i.e. osteonecrosis of the jaw and atypical diaphyseal femoral fracture) are needed. Odanacatib, a selective cathepsin K inhibitor, is a promising new approach to the inhibition of osteoclastic resorption, with the potential to uncouple bone formation from bone resorption. Results regarding its anti-fracture efficacy are expected in the coming months.