Department of Orthopedics, National Taiwan University Hospital

Denosumab is a potent anti-resorptive agent and is now widely used in the treatment of osteoporosis. Although denosumab has excellent effect to increase bone mass and prevent fracture in FREEDOM study with very low complications, even up to ten years, it's effect is reversible. After holding the drug, circulating denosumab levels fall rapidly, and bone resorption reaching twice baseline levels for about 6 months. How to prevent bone loss after denosumab therapy is an important issue, especially when considering the compliance, persistence, or other comorbidities of the patient. We want to verify if zoledronic acid could be used as a sequential therapy after denosumab to prevent rapid bone loss by randomized clinical trial.