High serum calcitonin levels in heroin addicts.

An involvement of calcitonin in the mechanism of pain perception has recently been hypothesized. In order to collect information about the relationship between this hormone and well known analgesic substances such as opioids, we have studied the serum levels of calcitonin in a group of heroin addicts, finding higher average concentrations than in normal subjects of matched age and sex. In these addicts there were no severe signs of impaired renal or hepatic function, or alterations of the serum levels of calcium and phosphate. So we think that opioids, in a direct or indirect way, can stimulate the secretion of calcitonin.