Endocrine Abstracts

Denosumab is an effective treatment of osteoporosis that leads to substantial increases in bone mass and clinically important reductions in fracture risk with few side effects. Most patients should continue treatment; however, some patients may need to discontinue treatment due to co-morbidities or side effects. Furthermore, some patients want to discontinue treatment because of normal or near-normal BMD and absence of fractures after years on treatment. Unlike bisphosphonates but like most other pharmacological treatments, there is no continuing effect of denosumab after discontinuing the administration. Due to the accumulation of RANKL and possibly osteoclasts during treatment with denosumab a rebound activation of bone resorption is seen in patients discontinuing denosumab after more than 1-2 years of treatment. This can partly be prevented by the administration of bisphosphonates, primarily zoledronate. The patients need frequent monitoring with p-CTX and in some cases multiple administrations of zoledronate during the first year after discontinuation in order to prevent bone loss.