A review of the physiological bases of the anorexic action of phenylpropanolamine (d,1-norephedrine).

Phenylpropanolamine (PPA) is a phenethylamine that induces a variety of effects including anorexia and weight loss. The present review compares the acute anorexic effects of PPA with those of amphetamine in animals and humans, describes the persistent chronic effects of PPA on feeding as well as differences in anorexic potency between the norephedrine enantiomers (d-norephedrine less than 1-norephedrine) and summarizes the generality of PPA anorexia. The review also describes the putative mechanisms by which PPA is thought to reduce feeding behavior including alteration of gastric emptying and interaction with central nervous system neurons.