What is the recommended dosage and administration of Metoclopramide (MET) for treating nausea and vomiting?

Metoclopramide Dosage and Administration for Nausea and Vomiting

For treating nausea and vomiting, metoclopramide should be administered at a dose of 10 mg orally three to four times daily before meals, or 10 mg intravenously/intramuscularly for more severe symptoms. 1, 2

Oral Administration

• Standard oral dosage is 10-30 mg 3-4 times daily before meals 3
• For mild to moderate nausea and vomiting, oral administration is preferred when tolerated 1, 2
• Oral metoclopramide is typically administered 30 minutes before meals and at bedtime 4
• For diabetic gastroparesis-related nausea, 10 mg four times daily has shown efficacy in reducing symptoms 4

Parenteral Administration

• For severe nausea and vomiting or when oral administration is not feasible, intravenous or intramuscular routes are recommended 1
• IV administration should be given slowly over 1-2 minutes for single doses 1
• The standard IV/IM dose is 10 mg; however, doses up to 20 mg may be used for severe symptoms 1, 2
• For chemotherapy-induced nausea and vomiting:
  • Administer IV infusion slowly over at least 15 minutes
  • Give 30 minutes before chemotherapy
  • Repeat every 2 hours for two doses, then every 3 hours for three doses
  • For highly emetogenic regimens: 2 mg/kg per dose
  • For less emetogenic regimens: 1 mg/kg per dose 1, 2

Special Populations

• For patients with renal impairment (creatinine clearance <40 mL/min), start with approximately half the recommended dosage 1, 2
• Dosage may be increased or decreased based on clinical efficacy and safety considerations 1
• Metoclopramide undergoes minimal hepatic metabolism and can be used at standard doses in patients with advanced liver disease who have normal renal function 1, 2

Duration of Treatment

• Parenteral metoclopramide should generally be limited to 1-2 days when possible 5
• Oral preparations are typically recommended for 4-12 weeks of therapy 5
• For refractory nausea and vomiting, adding dopamine antagonists to serotonin antagonists and corticosteroids may be beneficial 3

Adverse Effects and Monitoring

• The most common adverse reactions include restlessness, drowsiness, fatigue, and lassitude 5
• Extrapyramidal symptoms can occur, particularly with high dosage or prolonged use 5, 6
• If acute dystonic reactions occur, administer 50 mg diphenhydramine intramuscularly 1, 2
• Monitor for sedation, which typically precedes respiratory depression 3
• For patients reporting previous episodes of nausea during past exposure to opioids, prevention may include pretreatment with metoclopramide around the clock for the first few days 3

Alternative Formulations

• Rectal administration (25 mg suppositories) may be effective when oral dosing fails 7
• Subcutaneous administration (10 mg every 6 hours) has shown efficacy in treating gastroparesis with minimal side effects 8

Clinical Pearls

• Tolerance to nausea typically develops within a few days of starting treatment 3
• Rule out other causes of nausea (constipation, other medications) before attributing symptoms solely to the primary condition 3
• Metoclopramide has both central and peripheral effects and is recommended as first-line for the management of chronic nausea 3