Indication For use in the management of the manifestations of psychotic disorders and for the control of severe nausea and vomiting in adults. Mechanism of action Binds to the dopamine D1 and dopamine D2 receptors and inhibits their activity. The mechanism of the anti-emetic effect is due predominantly to blockage of the dopamine D2 neurotransmitter receptors in the chemoreceptor trigger zone and vomiting centre. Perphenazine also binds the alpha andrenergic receptor. This receptor's action is mediated by association with G proteins that activate a phosphatidylinositol-calcium second messenger system.