Metopimazine is a dopamine D2 receptor antagonist primarily used as an antiemetic to prevent and treat nausea and vomiting. It belongs to the phenothiazine derivative class but has minimal central nervous system penetration compared to other dopamine antagonists. This limited brain penetration reduces the risk of central side effects such as sedation and extrapyramidal symptoms. Metopimazine works mainly by blocking dopamine receptors in the chemoreceptor trigger zone (CTZ) outside the blood–brain barrier. It is commonly prescribed for nausea and vomiting associated with gastroenteritis, migraine, drug intolerance, and postoperative conditions. The drug is available in oral, suppository, and injectable forms for flexible administration. It is often preferred when strong central anti-dopaminergic effects are undesirable. Metopimazine is generally well tolerated with fewer neurological adverse effects than similar agents like metoclopramide. However, mild side effects such as drowsiness, dry mouth, or hypotension may occur. Overall, metopimazine is an effective and relatively safe antiemetic widely used in clinical practice.
