Endocrine Abstracts

Osteoporosis is characterized by decreased bone mineral density (BMD) and deterioration of bone microarchitecture increasing fracture risk. The main goal of osteoporosis treatment is preventing osteoporotic fractures. The most important predictor of treatment mediated fracture risk reduction is the increase in BMD. Treatment of osteoporosis falls into three pharmacological classes: antiresorptive agents (SERMs, oestrogen, bisphosphonates (BP), denosumab), osteo-anabolic drugs (teriparatide, abaloparatide), and dual-action drug romosozumab (mAb inhibiting sclerostin). The most commonly used are antiresorptive therapies. We switch from less potent raloxifene or ibandronate to more potent oral BPs alendronate or risedronate, or to the most potent antiresorptive drugs zoledronic acid i.v. or denosumab s.c., when more potent treatment and hip fracture prevention is needed. Namely, with raloxifene and ibandronate no significant reductions of non-vertebral or hip fractures were seen. When there are indications to discontinue denosumab a BP should be introduced. If denosumab treatment was short (1 year) an oral agent will do; after long-term treatment zoledronic acid should be applied 6 and 12 months after the last denosumab injection. In the case of treatment failure with a potent antiresorptive (significant decrease in BMD or new fractures after 12 months of adequate osteoporosis treatment) an anabolic agent is usually introduced for 24 months or dual-acting romosozumab for 12 months. It is obligatory to switch from anabolic or dual-action agent to antiresorptive agent when anabolic treatment is accomplished. In patients with very high fracture risk or those with very low BMD (T score< -3 SD) at presentation the initial osteo-anabolic treatment should be introduced. Anabolic agents induce the fastest increase of BMD and reduce fracture risk more rapidly and to a greater extent than antiresorptive medications. After atypical femoral fracture or osteonecrosis of the jaw caused by long-term BPs or denosumab therapy, an osteo-anabolic agent can be introduced if no contraindications exist.