• See Also
  1. Antiemetic
  • Indications
  1. Gastroesophageal Reflux
  2. Gastroparesis
  3. Nausea or Vomiting
  4. Hyperemesis Gravidarum
  5. Migraine Headache
  • Contraindications
  1. Small Bowel Obstruction
  2. Bowel Perforation
  • Mechanism
  1. Substituted benzamide that is a derivative of para-aminobenzoic acid (PABA), structurally similar to Procainamide
  2. Effects
    1. Dopamine Antagonist (D2) that has Antiemetic activity at the Medulla chemoreceptive Trigger Zone
    2. Prokinetic effects on gastrointestinal Smooth Muscle
    3. Increases gastric emptying
    4. Increases lower esophageal sphincter pressure and may reduce GERD
  • Dosing
  • Adults
  1. GERD: 10 mg orally four times daily taken 30 min before meals and before bedtime
  2. Gastroparesis: 10 mg PO/IV/IM four times daily taken 30 min before meals and before bedtime
  3. Nausea or Vomiting: 10 mg PO/IV/IM every 6 hours as needed
  4. Migraine Headache IV: 10 mg slow IV (see Akathisia below) or 10 mg orally with NSAID
  5. GI Procedure (UGI, Small Bowel intubation): 10 mg IV
  • Dosing
  • Children (off-label)
  1. GERD: 0.4 to 0.8 mg/kg/day divided four times daily
  2. GI Procedure (UGI, Small Bowel intubation)
    1. Age <6 years old: 0.1 mg/kg IV
    2. Age 6 to 14 years old: 2.5 to 5 mg IV
    3. Age >14 years old: 10 mg IV (adult dosing)
  • Safety
  1. Pregnancy Category B
  2. Unknown safety in Lactation
  • Adverse Effects
  1. Tardive Dyskinesia
    1. Irreversible with high dose and longterm use >3 months
    2. Avoid prolonged use >3 months
  2. Akathisia or other Extrapyramidal Side Effects
    1. Higher risk in elderly and children
    2. Common with IV administration if bolused quickly
    3. Best infused slowly over 15 minutes
    4. Treat reaction with Diphenhydramine 50 mg IV or IM
  3. Neurologic
    1. Sedation
    2. Agitation
    3. Seizures
    4. Hallucinations
  4. Gastrointestinal
    1. Constipation
    2. Diarrhea
  5. Endocrine
    1. Hyperprolactinemia
    2. Galactorrhea
  • Drug Interactions
  1. MAO Inhibitors
    1. Significant Hypertension risk
  2. Antipsychotic Drugs
    1. Risk of Neuroleptic Malignant Syndrome
  3. CYP2D6 Inhibitors (e.g. Fluoxetine)
    1. May worsen Extrapyramidal Side Effects
  4. Metoclopramide increases absorption of other drugs
    1. Aspirin
    2. Bupropion
  • Pharmacokinetics
  1. Well absorbed
  2. Metabolized in the liver 50%
  3. Renal excretion in urine
  • Resources
  1. Metoclopramide (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=de55c133-eb08-4a35-91a2-5dc093027397
  • References
  1. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 46-7
  2. Hamilton (2020) Tarascon Pocket Pharmacopoeia