Calcitonin in the prevention and treatment of glucocorticoid-induced osteoporosis

Calcitonin inhibits bone resorption by its direct inhibition of osteoclasts. Its efficacy in the prevention and treatment of glucocorticoid-induced osteoporosis has been tested in only a small number of studies. The two randomised, placebo-controlled trials published do not show any significant increase in bone mass. The unblinded trials have shown more positive effects on spinal bone density, but there are substantial differences in the outcome of these trials which are difficult to explain. Injectable calcitonin may have a greater effect than the nasal spray preparation, but its use is limited by a high incidence of side effects and low patient acceptability. There is no evidence that calcitonin reduces the fracture rates in these patients as there have been no studies of sufficient size to address this question. Given the availability of other therapeutic options of proven efficacy for bone protection in patients receiving long-term glucocorticoids, calcitonin should be regarded as a second-line agent.