Prochlorperazine is a piperazine phenothiazine, is an oral and parenteral antiemetic and antipsychotic agent. Prochlorperazine is most closely related to chlorpromazine. Prochlorperazine is mainly used for the management of nausea and vomiting but it shares many of the actions and adverse effects of the antipsychotics. It was approved by the FDA in 1956. an antiemetic drug and used to prevent nausea and vomiting. it blocks postsynaptic dopamine receptors in the mesolimbic system and increases dopamine turnover by blockade of the D2 receptor. The decrease in dopamine neurotransmission has been found to correlate with the antipsychotic effects. Dopamine blockade in the chemoreceptor trigger zone accounts for the antiemetic effects. It possesses moderate anticholinergic and alpha-adrenergic receptor blocking effects. Blockade of alpha-I adrenergic receptors produces sedation; muscle relaxation; and cardiovascular effects such as hypotension, reflex tachycardia, and minor changes in ECG patterns.