Metoclopramide is a dopamine antagonist and prokinetic agent indicated for the short-term treatment of adults with diabetic gastroparesis. It accelerates gastric emptying and increases lower esophageal sphincter tone, providing symptomatic relief from nausea and vomiting associated with delayed gastric emptying. This medication is also used to prevent postoperative nausea and vomiting and as an adjunct in radiographic procedures to facilitate small bowel intubation. Its mechanism involves central and peripheral dopamine receptor blockade, alongside moderate 5-HT3 receptor antagonism.

Features

• Active ingredient: Metoclopramide hydrochloride
• Available formulations: Oral tablets, orally disintegrating tablets, oral solution, injectable solution
• Standard strengths: 5 mg and 10 mg tablets; 5 mg/5 mL solution; 5 mg/mL injection
• Pharmacologic class: Dopamine D2 receptor antagonist, prokinetic agent
• Half-life: Approximately 5–6 hours
• Metabolism: Hepatic via oxidation and glucuronidation
• Excretion: Primarily renal (approximately 85%)

Benefits

• Accelerates gastric emptying and intestinal transit time in diabetic gastroparesis
• Provides effective antiemetic action through central dopamine receptor blockade
• Reduces symptoms of nausea and vomiting in multiple clinical scenarios
• Enhances radiographic visualization during upper GI series through improved motility
• Offers flexible administration routes including oral, intravenous, and intramuscular
• Demonstrates rapid onset of action, particularly with parenteral administration

Common use

Metoclopramide is primarily prescribed for the short-term (4–12 weeks) management of symptomatic diabetic gastroparesis in adults. It is used to relieve symptoms including nausea, vomiting, heartburn, and persistent fullness after meals. The medication is also employed for the prevention of postoperative nausea and vomiting when conventional therapies are ineffective or inappropriate. Additionally, it facilitates small bowel intubation during radiographic procedures and stimulates gastric emptying and intestinal transit of barium. Off-label uses include management of chemotherapy-induced nausea and vomiting, though other antiemetics are generally preferred for this indication.

Dosage and direction

For diabetic gastroparesis in adults: 10 mg orally 30 minutes before each meal and at bedtime for 2–8 weeks. The maximum recommended duration is 12 weeks due to risk of tardive dyskinesia. For postoperative nausea/vomiting prevention: 10–20 mg IM or IV near end of surgical procedure. For radiographic procedures: 10 mg IV as a single dose. Renal impairment adjustment: CrCl <40 mL/min requires 50% dose reduction. Hepatic impairment: Use with caution and consider dose reduction. Administration instructions: Oral tablets should be taken with water; orally disintegrating tablets placed on tongue; injection administered slowly IV over 1–2 minutes to minimize akathisia.

Precautions

Metoclopramide carries a black box warning for tardive dyskinesia, which may be irreversible and more likely with prolonged use or higher doses. Elderly patients, particularly women, are at increased risk. Monitor for involuntary movements of face, tongue, or extremities. May cause parkinsonian symptoms, particularly in elderly patients or those with Parkinson’s disease. Use with caution in patients with depression due to potential for worsening symptoms. May elevate prolactin levels, potentially causing galactorrhea, amenorrhea, or gynecomastia. Can cause fluid retention; use cautiously in patients with congestive heart failure, cirrhosis, or hypertension. May mask underlying mechanical obstruction; ensure proper diagnosis before administration.

Contraindications

Patients with known hypersensitivity to metoclopramide or any component of the formulation. Concomitant use with medications likely to cause extrapyramidal reactions. History of tardive dyskinesia. Pheochromocytoma due to risk of hypertensive crisis. Gastrointestinal obstruction, perforation, or hemorrhage. Epilepsy or seizure disorders (may lower seizure threshold). Concurrent use with MAO inhibitors within 14 days. Patients at increased risk of methemoglobinemia or with NADH cytochrome b5 reductase deficiency.

Possible side effect

Common (≥1%): Restlessness, drowsiness, fatigue, insomnia, headache, dizziness. Gastrointestinal: Nausea, diarrhea. Neurological: Akathisia, acute dystonic reactions (particularly in young adults). Endocrine: Hyperprolactinemia. Serious: Tardive dyskinesia (risk increases with duration and cumulative dose), neuroleptic malignant syndrome, depression, suicidal ideation, seizures, methemoglobinemia (especially in neonates). Cardiovascular: Bradycardia, tachycardia, hypertension, hypotension. Hematologic: Agranulocytosis, neutropenia. Hepatic: Elevated liver enzymes. Allergic reactions including urticaria, bronchospasm.

Drug interaction

Strong CYP2D6 inhibitors (fluoxetine, paroxetine, quinidine): May increase metoclopramide exposure. Dopaminergic agents (levodopa, bromocriptine): Antagonistic effects. CNS depressants (alcohol, benzodiazepines, opioids): Additive sedation. Serotonergic drugs (SSRIs, SNRIs, tramadol): Increased risk of serotonin syndrome. Drugs that prolong QT interval (antiarrhythmics, antipsychotics): Potential additive effect. Acetaminophen: May increase absorption. Digoxin: Possible decreased absorption. Cyclosporine: Increased bioavailability. Succinylcholine: Prolonged neuromuscular blockade. Insulin: May affect glycemic control requiring adjustment.

Missed dose

If a dose is missed, administer as soon as possible unless it is nearly time for the next scheduled dose. Do not double doses to make up for a missed dose. For patients taking metoclopramide before meals, if a meal is missed, the corresponding dose should generally be omitted. Maintain regular dosing schedule to ensure consistent therapeutic effect. Contact healthcare provider if multiple doses are missed or if questions arise about dosing schedule.

Overdose

Symptoms may include drowsiness, disorientation, extrapyramidal reactions, seizures, and methemoglobinemia. Cardiovascular effects include bradycardia, tachycardia, hypertension, or hypotension. In cases of acute overdose, employ supportive measures including gastric lavage if presented early. Activated charcoal may be effective. Monitor cardiac function and neurological status. Extrapyramidal symptoms may be managed with diphenhydramine 25–50 mg IM or IV or benztropine 1–2 mg IM or IV. Seizures may require benzodiazepines. Methemoglobinemia may be treated with methylene blue 1–2 mg/kg IV. Hemodialysis is not effective due to high protein binding.

Storage

Store at controlled room temperature 20–25°C (68–77°F). Protect from light and moisture. Keep oral solution in original container; do not freeze. Injectable solution should be inspected for particulate matter and discoloration before administration. Keep all medications out of reach of children and pets. Do not use beyond expiration date printed on packaging. Dispose of unused medication through take-back programs or according to FDA guidelines.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Metoclopramide is a prescription medication that should be used only under supervision of a qualified healthcare professional. The prescribing physician should be consulted for complete information regarding indications, dosage, warnings, and precautions. Individual patient response may vary. Never discontinue or change dosage without medical consultation. Report any adverse effects to healthcare provider promptly.

Reviews

Clinical studies demonstrate metoclopramide’s efficacy in diabetic gastroparesis, with approximately 60-70% of patients showing symptomatic improvement. Many gastroenterologists note its value as a prokinetic agent despite safety concerns. Patients frequently report significant relief from nausea and vomiting, though some discontinue due to side effects, particularly restlessness and fatigue. The risk of tardive dyskinesia remains a significant consideration in long-term use. Most experts recommend limiting treatment duration to 12 weeks maximum and employing the lowest effective dose. Comparative studies show superior efficacy to placebo in gastroparesis symptoms, though newer agents are being investigated for improved safety profiles.