Anabolic Agents in the Treatment of Postmenopausal Osteoporosis

Osteo-anabolic agents directly stimulate the differentiation and activity of osteoblasts, with a secondary increase in osteoclastic activity and bone remodeling, as seen with PTH receptor agonists (PTH, teriparatide, and abaloparatide), or with a concomitant decrease of bone resorption, as seen with sclerostin Ab (romosozumab). The resulting effect of these anabolic therapies is a prominent increase in trabecular bone volume and a variable increase in cortical bone volume (romosozumab > abaloparatide > teriparatide). Anabolic therapies have shown a superior antifracture efficacy compared to antiresorptive. So far, the use of anabolic agents has been limited to second, even third-line therapy after failure of antiresorptives, mainly for reasons of costs. However, recent algorithms and guidelines have started to reposition anabolic therapy as a potential first-line therapy in patients at very high/imminent fracture risk. After anabolic therapy, an antiresorptive therapy is required because of the quick reversibility of the drug’s benefits when its maximal duration of use has been reached.