The analgesic effects of Clomipramine and Carbamazepine individually, and in combination with pethidine using the formalin test

Abstract

The aim of the present study was to investigate the analgesic effects of clomipramine (a tricyclic antidepressant) and carbamazepine (an anticonvulsant) individually, and in combination with pethidine (a narcotic) in the formalin test. Several doses of each drug were used in the experiment. The lowest dose that caused significant change in the late phase of formalin test was used in combination with pethidine. The pethidine dose used in the combination experiments had no significant change in the late phase of formalin test. The formalin test was performed by injecting a dilute solution (20 jJl of 1% formalin in 0.9% NaCI) subcutaneously in the right hind paw of both the controls and the test animals. The time in seconds) spent in licking and, or lifting the paw was monitored in blocks of 5 minutes for 1 hour. The drugs or vehicle were injected 30 minutes prior to the formalin test. The drugs were administered intraperitoneally.