Reglan

Reglan is the brand name for metoclopramide, a medication used as an antiemetic and prokinetic agent. It is prescribed to relieve nausea and vomiting from chemotherapy, surgery, and other causes, and to hasten gastric emptying in conditions such as gastroparesis. It may also be used for certain gastroesophageal reflux symptoms when prokinetic therapy is indicated. The drug is available in oral forms (tablets and syrup) and as injections for intravenous or intramuscular use.

Mechanism of action involves two primary effects. Metoclopramide acts as a dopamine D2 receptor antagonist in the chemoreceptor trigger zone, reducing nausea and vomiting. At lower doses it can have agonist activity at serotonin 5-HT4 receptors, which enhances upper gastrointestinal motility by increasing acetylcholine release, thereby improving gastric emptying and increasing lower esophageal sphincter tone.

Dosing and administration vary by indication and patient factors. In adults, antiemetic regimens commonly use about 10 mg up to four times daily, while treatment for gastroparesis typically involves 10 mg before meals and at bedtime. Treatment is generally short term due to safety concerns; long-term use is associated with an increased risk of tardive dyskinesia and other extrapyramidal symptoms, so many guidelines limit use to 12 weeks or less and often recommend not exceeding a total daily dose of about 40 mg.

Adverse effects can include drowsiness, fatigue, restlessness, and extrapyramidal symptoms such as dystonias or akathisia. Rare but serious effects include tardive dyskinesia and, less commonly, neuroleptic malignant syndrome. Metoclopramide can increase prolactin levels, potentially causing galactorrhea or gynecomastia. It interacts with other central nervous system depressants and may affect the absorption of other oral medications.

Contraindications include suspected GI obstruction, perforation, or GI hemorrhage. Caution is advised in patients with epilepsy, Parkinson’s disease, or a history of tardive dyskinesia, and use during pregnancy should be limited to necessary cases after discussion of risks.