ANALGESIC EFFECT OF INTRANASAL AND INTRAMUSCULAR SALMON-CALCITONIN INPOSTMENOPAUSAL OSTEOPOROSIS - A DOUBLE-BLIND, DOUBLE-PLACEBO STUDY

Different types of calcitonin (porcine, human, salmon) are used in the management of bone diseases characterized by a high bone turnover; su ch as post-menopausal osteoporosis and Paget's disease; recently, salm on calcitonin has become clinically available as an intranasal (i.n) s pray. An analgesic effect has also been described for calcitonins, bot h in experimental animals and humans, but only a few studies in humans were placebo controlled. The aim of this study was to compare the ana lgesic efficacy of i.n. and intramuscular (i.m.) salmon calcitonin (sC T) and of placebo in women affected by painful post-menopausal osteopo rosis, in a double-blind, double-placebo trial. Twenty-eight women wer e randomly allocated to one of the following treatments: 1) i.n. sCT 2 00 U/day plus i.m. placebo; 2) i.n. placebo plus i.m. sCT 100 U/day; a nd 3) i.n. and i.m. placebo. Each treatment lasted four weeks, and the pain score was evaluated weekly by means of a visual analogic scale ( VAS). Twenty-four women completed the trial; with i.n. sCT, the pain s core decreased significantly by the second week of treatment (p<0.05); with i.m. sCT and with placebo, the pain score decreased significantl y only by the fourth week (p<0.05), so that the final pain scores obta ined with the three treatments were not different. We conclude that i. n. sCT was probably more rapid, but not more effective than i.m. sCT o r placebo in decreasing pain in post-menopausal osteoporosis.