Osteoporosis: long-term treatment versus drug holiday-what is the evidence?

The occurrence of multiple vertebral fractures after discontinuation of denosumab in the treatment of osteoporosis has reopened the debate on the optimal treatment duration and drug holidays. In principle, there is a difference in this regard between the discontinuation of medications such as bisphosphonates and substances without bone retention such as selective estrogen receptor modulators (SERMs), denosumab or teriparatide. Even after the end of application bisphosphonates have a very long half-life in the bones. After cessation of drug intake there is a slow, slight increase of bone turnover markers. Even after cessation of the SERM raloxifene, a decline in bone density can be observed, as with the termination of teriparatide. In contrast to these osteoporosis medications, after cessation of denosumab, a steep and rapid increase in markers of bone resorption above baseline levels ("rebound") and a reduction in bone mineral density to initial values can be observed. Osteoporosis is a disease that carries an increased risk of fracture, which is reduced for the duration of osteoporosis treatment. In certain situations, the fracture risk is only temporarily raised. In these situations, cessation of the osteoporosis treatment is possible. Beyond these special clinical situations, however, osteoporosis needs to be addressed as a chronic disease with a permanently increased fracture risk and the indication for therapy should be evaluated according to the extent of the risk of fracture. What happens after discontinuation of anti-osteoporosis drugs? The various effects on bone turnover markers, bone mineral density and fracture incidence of the individual drug groups are presented in detail, as are the resulting recommendations of the task forces of the American Society of Bone and Mineral Research (ASBMR) and the European Calcified Tissue Society (ECTS).