Analgesic action of clonixin, nifedipine and morphine using the formalin test

1. The analgesic effect of ClX, nifedipine, metamizol, indoprofen and morphine in the pain induced by formalin injection (formalin test) was studied. 2. Attempts to demonstrate tolerance to ClX were unsuccessful. 3. In the analgesic test nifedipine and morphine are approximately 10 times more potent than ClX. 4. The present results suggest that the analgesic action of ClX is not mediated by mu 1, delta or kappa-opioid receptors and the anti-nociceptive effect of nifedipine may be associated with the blockade of the transmembrane inward movements of calcium.