Analgesic effects of calcitonin.

The analgesic activity of salmon calcitonin (subcutaneous or intranasal) has been demonstrated in several prospective clinical trials, in patients suffering different painful skeletal conditions, including recent nontraumatic osteoporotic vertebral fractures. The mechanism of the analgesic effect of calcitonin is not clear. It is possible that specific binding sites for salmon calcitonin exist in the brain. Another explanation is that changes in descending serotonergic modification on the sensory transmission mediated by C afferents contribute to the analgesic effects of calcitonin on pain in osteoporotic patients. From the clinical point of use, the analgesic effect of calcitonin is beneficial throughout the whole period of medical treatment of osteoporotic patients. Salmon calcitonin in a daily dose of 100 IU subcutaneously or 200 IU intranasally reduces dramatically the back pain (p < 0.0005) after a recent osteoporotic vertebral fracture, and promotes the early mobility of patients. The finding that injectable or intranasally administered salmon calcitonin effectively controls severe pain in osteoporotic patients with a recent vertebral fracture, allowing them earlier mobility in combination with a reduction of the urinary hydroxyproline excretion, and a limitation of the considerable bone loss that may occur during prolonged bed rest, make this therapeutic scheme attractive.