The effects of d- and l-fenfluramine (and their interactions with d-amphetamine) on cortisol secretion.

Twelve normal weight healthy male volunteers participated in a double-blind, placebo-controlled trial of the effects of d- and l-fenfluramine, d-amphetamine, and the interactions between the two isomers of fenfluramine with amphetamine, on cortisol secretion. d-Fenfluramine and d-amphetamine in combination produced the greatest cortisolaemic effect, suggesting that they act by differing neurochemical pathways. d-Fenfluramine produced a significant effect, but l-fenfluramine produced little effect, suggesting that the cortisol-releasing properties of racemic fenfluramine reside in the d-isomer.