Increase of pain threshold by calcitonin during electrical stimulation of the dental pulp. Investigations in healthy volunteers with regard to plasma concentration.

A randomized, double-blind study was performed to test the analgesic effect of salmon calcitonin (sCT). The pain threshold of ten healthy subjects was measured during electrical stimulation of the dental pulp. Each subject underwent four different tests, whereby sCT at doses of 50 IU, 100 IU and 200 IU or placebo was administered subcutaneously. For all subjects, four curves were obtained that showed the time course of the intensity of electrical stimulation needed to attain the pain threshold, up to 240 min post-application. Parallel to these studies, radioimmunoassay was performed to determine the plasma level at the time at which the maximum concentration was expected, i.e. 15 min after the injection. The pain threshold was raised by 10 mA or more with all three doses of calcitonin tested. The latent period before the threshold had risen by 10 mA declined in parallel with the doses of sCT administered (from 82 to 40+min), whereas the duration of action was increased (from 95 to over 182 min). The maximal threshold change was also significantly dependent on the dosage: with placebo the maximal change was 4 mA, while with sCT 50, sCT 100, and sCT 200 it was 14, 17 and 18 mA, respectively. The plasma levels of sCT and its analgesic activity were significantly correlated, as was demonstrated by means of linear regression based upon the bilogarithmic transformation of the plasma concentration. Altogether, the results prove conclusively that calcitonin given systemically possesses primary analgesic efficacy, a property that fits well into its spectrum of activity in the treatment of (painful) bone diseases.

RCT Entities:   Population Interventions Outcomes