metoklopramid

Metoklopramid, more commonly known as metoclopramide, is a prescription medication with antiemetic and prokinetic properties. It is a dopamine D2 receptor antagonist with additional activity at serotonin receptors. Centrally, it blocks dopamine receptors in the chemoreceptor trigger zone to reduce nausea and vomiting; peripherally, it enhances gastric motility by increasing acetylcholine release in the upper gastrointestinal tract, which can speed gastric emptying and improve lower esophageal sphincter tone.

Indications include prevention of postoperative nausea and vomiting, prevention and treatment of chemotherapy- and radiotherapy–associated nausea, and short-term management of gastroparesis and certain cases of gastroesophageal reflux with delayed gastric emptying. It may also be used for short-term relief of acute migraine–associated nausea. Metoclopramide can be given by oral, intramuscular, or intravenous routes, depending on the indication and setting.

Pharmacokinetics and dosing: Metoclopramide is reasonably well absorbed orally, with onset typically within 30 to 60 minutes. The elimination half-life is about 5 to 6 hours in adults, with hepatic metabolism and renal excretion of metabolites. Because of concerns about movement disorders, the shortest effective duration and the lowest effective dose should be used. Long-term use is avoided due to the risk of tardive dyskinesia.

Adverse effects and safety: Common side effects include drowsiness, fatigue, and restlessness. Prolactin elevation can cause galactorrhea or menstrual irregularities. Extrapyramidal symptoms (such as dystonia or akathisia) can occur, particularly in younger patients or with higher doses. Rare but serious risks include tardive dyskinesia with prolonged use and, less commonly, neuroleptic malignant syndrome. Metoclopramide should be avoided in patients with Parkinson’s disease and used with caution in those with seizure disorders or in the elderly.

Contraindications and interactions: Contraindicated in individuals with documented hypersensitivity to metoclopramide and in those with certain mechanical gastrointestinal disorders, such as obstruction, perforation, or hemorrhage. Caution is advised when combining with other central nervous system depressants or other dopamine antagonists.