Activities of five antidepressants in a behavioral pain test in rats.

Various clinical and experimental reports indicate that antidepressant drugs can have analgesic properties. The authors tested successively the anti-nociceptive activity of desipramine, clomipramine, maprotiline, viloxazine and nomifensine on the acute experimental pain model designed by Charpentier. At 25 mg/kg, desipramine showed a marked antalgic action. Clomipramine and maprotiline had a similar though much weaker action. On the other hand, nomifensine and viloxazine did not reduce pain perception; their effects on the parameters studied were variable. The usefulness of the test itself is discussed and suggestions are made regarding the relations between the analgesic potency of the drugs and the main neurotransmitter system they are assumed to act on.