Potentiation of LSD-induced stimulus control by fluoxetine in the rat.

The present investigation examined the interaction between fluoxetine enantiomers and LSD in rats trained with LSD as a discriminative stimulus. The dose response relationships for LSD alone and in combination with either (+)- or (-)-fluoxetine were determined. In both instances, the LSD dose response relationship was shifted to the left. However, statistical significance was observed only for the (+)- enantiomer. It is concluded that the effects of LSD as a discriminative stimulus are potentiated by the acute administration of fluoxetine. These results are consistent with anecdotal reports of interactions between LSD and acutely administered SSRIs in humans.