IM Prochlorperazine Dosing for Severe Nausea and Vomiting
For intramuscular administration in adults, inject 5 to 10 mg deeply into the upper outer quadrant of the buttock, repeating every 3 to 4 hours as needed, with a maximum total daily dose of 40 mg. 1
Standard IM Dosing Protocol
- Initial dose: 5-10 mg IM injected deeply into the upper outer quadrant of the buttock 1
- Frequency: Repeat every 3-4 hours if necessary 1
- Maximum daily dose: Do not exceed 40 mg per day total IM dosage 1
- Injection technique: Deep IM injection only; subcutaneous administration is not advisable due to local irritation 1
Special Population Considerations
Elderly and Debilitated Patients
- Start at the lower end of the dosing range (5 mg) 1
- Increase dosage more gradually than in younger patients 1
- Monitor closely for hypotension and neuromuscular reactions, as elderly patients are more susceptible 1
Perioperative Use
- Preoperative: 5-10 mg IM given 1-2 hours before anesthesia induction (may repeat once in 30 minutes if needed) 1
- Intraoperative/Postoperative: 5-10 mg IM to control acute symptoms during or after surgery (repeat once if necessary) 1
Critical Safety Warnings
Extrapyramidal Reactions
- Akathisia occurs in 16% of patients receiving prochlorperazine in the emergency department setting 2
- Dystonia occurs in 4% of patients 2
- These reactions typically develop within the first week of treatment 3
- Consider prophylactic diphenhydramine 50 mg to prevent or treat dystonic reactions 4
Contraindications and Precautions
- Absolute contraindications: CNS depression, concurrent use of adrenergic blockers 5
- Avoid in pediatric surgery patients - children are more prone to extrapyramidal reactions even at moderate doses 1
- Monitor for hypotension, particularly in unstable cardiac or trauma patients 1
- QT prolongation risk: Repeated doses can prolong QT interval and potentially precipitate torsades de pointes 6
Comparative Efficacy
Prochlorperazine demonstrates superior antiemetic efficacy compared to promethazine in the emergency department setting:
- Significantly faster symptom relief (mean 8.5 minutes for IV administration) 7
- Lower treatment failure rate (9.5% vs 31% for promethazine) 8
- Less sedation compared to promethazine (38% vs 71% reporting sleepiness) 8
Management of Refractory Symptoms
If nausea persists despite prochlorperazine:
- Add a serotonin antagonist such as ondansetron 6
- Consider adding dexamethasone for enhanced antiemetic effect 6
- For palliative care patients, prochlorperazine 5-10 mg can be given 3-4 times daily (IV or oral routes) 5
Common Pitfalls to Avoid
- Do not use subcutaneous route - causes local irritation 1
- Do not mix with other agents in the syringe 1
- Protect solution from light; discard if markedly discolored 1
- Do not exceed 40 mg total daily dose to minimize risk of extrapyramidal effects and tardive dyskinesia with prolonged use 1, 9
- Be vigilant for akathisia within the first week, as this is the most common extrapyramidal symptom (14% incidence) 3