Metoclopramide Dosing for Nausea and Vomiting
For general nausea and vomiting, the standard dose of metoclopramide is 10 mg orally or intravenously every 6 hours as needed, with a maximum of 40 mg per day. 1, 2, 3
Standard Dosing by Clinical Context
General Nausea and Vomiting (Non-Chemotherapy)
- 10 mg orally or IV every 4-6 hours as needed is the first-line dose for breakthrough nausea 1
- Maximum daily dose: 40 mg 1, 2
- Can be given as 10-40 mg per dose depending on severity 1
- For labor-related nausea: 10 mg IV as a single dose when symptoms develop 4
Low Emetogenic Risk Chemotherapy
- 10-40 mg orally or IV every 4-6 hours as needed 1
- Alternative: 12 mg orally or IV daily as scheduled dosing 1
High-Dose Chemotherapy (Cisplatin-Based)
- 2 mg/kg IV infused over 15 minutes, given 30 minutes before chemotherapy 2, 3, 5
- Repeat every 2 hours for 2 doses, then every 3 hours for 3 additional doses 2, 3
- For less emetogenic regimens: 1 mg/kg per dose may be adequate 2, 3
- Must be diluted in 50 mL parenteral solution for doses exceeding 10 mg 2, 3
Diabetic Gastroparesis
- 10 mg IV slowly over 1-2 minutes for severe symptoms 2, 3
- May require up to 10 days of IV therapy before transitioning to oral 2, 3
- Oral dosing can be initiated for early/mild manifestations 2, 3
Postoperative Nausea and Vomiting
- 10 mg IM near the end of surgery 2, 3
- Doses of 20 mg may be used for higher risk cases 2, 3
- Evidence shows limited efficacy: number-needed-to-treat is 9.1 for early vomiting and 10 for late vomiting 6
Pediatric Dosing
- Ages 6-14 years: 2.5-5 mg 2, 3
- Under 6 years: 0.1 mg/kg 2, 3
- For chemotherapy in children: 2 mg/kg IV (same as adults), though extrapyramidal reactions occur in 15% at this dose 7
- Number-needed-to-treat for early vomiting in children is 5.8 6
Critical Dosing Adjustments
Renal Impairment
- For creatinine clearance <40 mL/min: initiate at approximately one-half the recommended dose 2, 3
- Titrate up or down based on efficacy and tolerability 2, 3
Hepatic Impairment
- No dose adjustment required for patients with advanced liver disease if renal function is normal 2, 3
- Metoclopramide undergoes minimal hepatic metabolism 2, 3
Administration Guidelines
Intravenous Administration
- Standard 10 mg doses: administer slowly over 1-2 minutes 2, 3
- High-dose chemotherapy regimens: infuse over minimum 15 minutes 2, 3
- Dilute doses >10 mg in 50 mL normal saline (preferred) or other compatible solutions 2, 3
Route Selection
- IV/IM routes are preferred for severe symptoms or when oral intake is compromised 2, 3
- Oral administration is appropriate for mild-to-moderate symptoms or maintenance therapy 1, 2
Safety Considerations and Toxicity Management
Extrapyramidal Reactions
- If acute dystonic reactions occur: inject 50 mg diphenhydramine IM immediately 2, 3
- Symptoms usually subside rapidly with diphenhydramine 2, 3
- Alternative: benztropine 1-2 mg IV/IM if allergic to diphenhydramine 1
- Risk increases with doses ≥2 mg/kg, particularly in younger patients and with consecutive-day dosing 7
Duration Limitations
- Limit use to no more than 2 times per week for chronic nausea to prevent medication-overuse headache 1
- Long-lasting adverse effects (tremors, anxiety, depression) can persist for months even after short-term low-dose use 8
- Reserve for debilitating cases after other remedies have failed 8
Comparative Efficacy
- Metoclopramide shows mild superiority over haloperidol (1.92 vs 3.04 vomiting episodes) when both given at high doses 5
- For postoperative nausea, metoclopramide has modest efficacy with no significant anti-nausea effect, only anti-vomiting effect 6
- Ondansetron is generally preferred over metoclopramide for non-chemotherapy indications due to lack of extrapyramidal effects 9
Combination Therapy
- When metoclopramide fails, add an agent from a different drug class (haloperidol, olanzapine, or 5-HT3 antagonist) 1, 9
- For refractory chemotherapy-induced vomiting, five-drug combinations including metoclopramide 2 mg/kg with dexamethasone, droperidol, lorazepam, and diphenhydramine achieve complete protection in 61% of patients 10
- Around-the-clock dosing is strongly preferred over PRN dosing 9