domperidon

Domperidone is a dopamine D2 receptor antagonist with prokinetic and antiemetic effects. It acts peripherally in the gastrointestinal tract to enhance motility by blocking D2 receptors in the enteric nervous system, increasing lower esophageal sphincter tone and accelerating gastric emptying and intestinal transit. Its limited ability to cross the blood-brain barrier reduces central nervous system side effects compared with many other antiemetics.

Indications and regulatory status vary by country. Domperidone is used to treat symptoms of gastroparesis and functional dyspepsia and to relieve nausea and vomiting associated with delayed gastric emptying. It has been used off-label to promote lactation due to prolactin elevation in some settings. In the United States, domperidone is not FDA-approved, and its availability is restricted in many regions because of concerns about QT interval prolongation and rare but potentially fatal arrhythmias, especially at higher doses or in patients with cardiac risk factors.

Safety and cautions: Common side effects include dry mouth and abdominal discomfort. Hormonal effects such as galactorrhea, amenorrhea, and breast tenderness may occur. Cardiac risks include QT prolongation and torsades de pointes, particularly with concurrent QT-prolonging drugs, electrolyte disturbances, or underlying heart disease. Domperidone is contraindicated in individuals with known QT prolongation, certain cardiac conditions, and severe hepatic impairment; pregnancy and lactation guidance varies by jurisdiction.

Pharmacokinetics: Domperidone has limited oral bioavailability due to first-pass metabolism and is metabolized in the liver, with excretion in urine and feces. Dosing is individualized, with emphasis on using the lowest effective dose to minimize risks.