The analgesic role of calcitonin following osteoporotic fracture.

Osteoporosis is a systemic skeletal condition characterized by decreased bone strength with consequent increased susceptibility to bone fracture. Fragility fractures in osteoporosis are often painful and result in loss of quality of life and disability. Salmon calcitonin (SCT) is a natural hormone that may assist in the management of osteoporotic patients following fracture by reducing fracture risk and decreasing pain. SCT is an antiresorptive agent which has been shown to reduce the risk of vertebral fractures (by 36%) in postmenopausal women with osteoporosis and previous fractures, with a safety profile comparable to placebo over long-term use. Clinical evidence suggests that SCT (with either subcutaneous and intranasal delivery) is an analgesic for the acute pain following osteoporotic fracture. Pain relief with SCT occurs after 1 week or less of treatment. Associated with this pain relief, vertebral fracture patients receiving SCT have been observed to have earlier mobilization compared with those receiving a placebo. Both preclinical and clinical data suggest a central analgesic effect for SCT. The mechanism(s) by which SCT induces pain relief has (have) not been conclusively shown. Neither a direct receptor-mediated action nor an indirect endorphin-mediated effect can be ruled out.