It is a substituted benzamide and is D2-receptor antagonist.
Mechanism of action:
It acts by blocking dopamine D2-receptor in the chemoreceptor trigger zone in the brain. It also causes increased action of the acetylcholine at muscarinic nerve endings in stomach resulting in more peristalsis and emptying of the upper part of the stomach.
It is primarily used in nausea and vomiting. It is also used in emptying of the stomach.
Administration and dosage:
It can be administered orally, IM or IV in the dose of 10 mg three times a day.
It causes antidopaminergic side effects i.e. twisting of the neck towards one side due to muscle spasm, diarrhea, sedation and extra pyramidal symptoms that are the main adverse effects of dopamine receptor blockers characterized by symptoms very similar to Parkinson’s disease and include tremor.