What is the recommended intravenous (IV) dose of metoclopramide for a patient weighing 39 kilograms (kg)?

Metoclopramide IV Dosing for a 39 kg Patient

For a patient weighing 39 kg, use pediatric weight-based dosing of metoclopramide rather than standard adult dosing, as the 40 kg threshold for adult dosing has not been reached. 1, 2

Weight-Based Dosing Threshold

• Children weighing less than 40 kg should receive pediatric weight-based dosing, while those at or above 40 kg transition to adult dosing protocols 1, 2
• At 39 kg, this patient falls just below the established cutoff and requires pediatric dosing calculations 2

Recommended Dosing by Indication

For Gastroparesis or General Antiemetic Use

• Standard dose: 10 mg IV administered slowly over 1-2 minutes 3
• This represents the typical adult dose that can be used for adolescents and larger pediatric patients approaching adult weight 4, 3
• May be repeated up to 3-4 times daily, with maximum daily dose not exceeding 30 mg 4

For Chemotherapy-Induced Nausea/Vomiting (High-Dose Regimen)

• Dose: 1-2 mg/kg IV (39-78 mg for this patient) 3, 5
• For highly emetogenic chemotherapy (cisplatin, dacarbazine): use 2 mg/kg per dose 3
• For less emetogenic regimens: 1 mg/kg per dose may be adequate 3
• Administer over at least 15 minutes, 30 minutes before chemotherapy 3
• Important: Doses exceeding 10 mg should be diluted in 50 mL parenteral solution 3
• Coadminister diphenhydramine to prevent extrapyramidal reactions, which occur in approximately 15% of patients at this dose level 6

For Facilitating Small Bowel Intubation or Radiological Examination

• For patients over 14 years: 10 mg IV (undiluted) over 1-2 minutes 3
• For patients 6-14 years: 2.5-5 mg IV 3
• Given this patient's weight of 39 kg (likely adolescent), the 10 mg dose is appropriate 3

Administration Guidelines

• Standard doses (10 mg): Administer slowly IV over 1-2 minutes 3
• High doses (>10 mg): Must be diluted in 50 mL of parenteral solution and infused over at least 15 minutes 3
• Preferred diluent is normal saline, which can be stored frozen for up to 4 weeks when combined with metoclopramide 3

Critical Safety Considerations

Duration and Maximum Dosing

• Limit treatment to 5 days maximum to minimize risk of tardive dyskinesia and extrapyramidal disorders 4
• Maximum daily dose: 30 mg across all indications 4

Extrapyramidal Reactions

• Risk increases in younger patients, with 15% experiencing extrapyramidal reactions and 33% experiencing akathisia at 2 mg/kg doses 6
• Prophylactic diphenhydramine should be administered with high-dose regimens 6, 7
• If acute dystonic reactions occur, administer 50 mg diphenhydramine IM immediately 3
• Akathisia (restlessness) occurs in approximately 9% of patients even with standard 10 mg doses 7

Common Adverse Effects

• Drowsiness is the most common side effect, impairing function in approximately 17% of patients 7
• Other effects include sedation, dizziness, and upset mood 8
• These effects are dose-independent and occur across all dosing ranges 7

Contraindications and Precautions

• Avoid in: Seizure disorders, pheochromocytoma, GI bleeding or obstruction 4
• Monitor for QT interval prolongation 8

Renal Impairment Adjustment

• If creatinine clearance is below 40 mL/min, initiate therapy at approximately one-half the recommended dosage 3
• Metoclopramide clearance correlates significantly with serum urea and creatinine levels 9

Clinical Pearls

• For standard antiemetic use in this 39 kg patient, 10 mg IV is the appropriate dose 4, 3
• This provides effective symptom control while minimizing adverse effects compared to higher weight-based dosing 7
• The 10 mg dose has been shown to be as effective as higher doses (20 mg or 40 mg) for conditions like acute migraine, with no additional benefit from dose escalation 7