CENTRAL ANALGESIC EFFECTS OF DESIPRAMINE, FLUVOXAMINE, AND MOCLOBEMIDE AFTER SINGLE ORAL DOSING - A STUDY IN HEALTHY-VOLUNTEERS

The antinociceptive effect of three antidepressants with different postulated modes of action, 75 mg desipramine, 225 mg fluvoxamine, and 450 mg moclobemide, was evaluated after single oral dosing in a randomized, double-blind, placebo-controlled crossover study in 10 healthy volunteers. Experimental pain thresholds (polysynaptic R-III reflex and subjective pain rating) were monitored over 23 hours. Compared with placebo, all drugs induced significant subjective pain threshold increases (maximal increase: desipramine, +20%; fluvoxamine, +17%; moclobemide, +13%). However, only desipramine (maximal increase, +25%) and moclobemide (maximal increase, +14%) displayed a significative effect on R-III threshold. Antidepressants thus exert an antinociceptive effect after a single oral dose. The level of their action apparently relies on the postulated mode of action.