Effect of fenfluramine challenge on cocaine craving in addicted male users

The authors studied the effects of a challenging dose of the serotonin (5-HT)-releaser/reuptake inhibitor d,l-fenfluramine (FEN) on spontaneous cocaine craving in a group of cocaine-addicted users in order to evaluate the involvement of serotonergic pathways in the modulation of craving for cocaine. Nineteen cocaine-dependent male inpatients received 60 mg of FEN or placebo (double-blind). Data were compared with those obtained in a previous study of another serotonergic probe, the partial postsynaptic agonist meta-chlorophenyl-piperazine (m-CPP). FEN significantly reduced cocaine craving and increased cortisol and prolactin when compared with placebo. When the responses to the two drugs were compared, there were no differences in the cortisol and prolactin rises, but m-CPP was a more potent inhibitor of cocaine craving than FEN. These data suggest that 5-HT releasers/reuptake inhibitors and serotonergic agents with greater postsynaptic activity should be further examined.