What is the recommended dosage of Stemetil (prochlorperazine) for adults and children?

Stemetil (Prochlorperazine) Dosing

For adults with nausea and vomiting, the standard dose of prochlorperazine (Stemetil) is 5-10 mg orally three to four times daily, with a maximum of 40 mg per day, or 25 mg as a suppository with a maximum of three doses per 24 hours. 1, 2

Adult Dosing by Indication

Nausea and Vomiting

• Oral tablets: 5-10 mg three to four times daily 2
• Maximum daily dose: 40 mg for resistant cases 2
• Rectal suppository: 25 mg, maximum three doses per 24 hours 1
• Intravenous: 2.5 mg by slow IV push has been shown effective and safe, particularly in acute settings 3
• Begin with the lowest recommended dosage and adjust based on individual response 2

Migraine-Associated Nausea (Adjunctive Therapy)

• Standard dose: 25 mg orally or by suppository 1
• Maximum: Three doses per 24 hours 1
• Administer 20-30 minutes before or with analgesics, NSAIDs, or ergotamine derivatives 1

Psychiatric Disorders

• Non-psychotic anxiety: 5 mg three to four times daily 2
  • Do not exceed 20 mg per day 2
  • Do not use for longer than 12 weeks 2
• Psychotic disorders/schizophrenia: 5-10 mg three to four times daily initially, titrating to 100-150 mg daily for severe cases 2

Pediatric Dosing

Critical Safety Warning

Prochlorperazine should NOT be used in children under 20 pounds (9 kg) or under 2 years of age, and should NOT be used in pediatric surgery. 2 Children are more prone to extrapyramidal reactions even at moderate doses 2, 4

Nausea and Vomiting in Children (Weight-Based)

• 20-29 lbs (9-13 kg): 2.5 mg once or twice daily, maximum 7.5 mg/day 2
• 30-39 lbs (14-18 kg): 2.5 mg two to three times daily, maximum 10 mg/day 2
• 40-85 lbs (18-39 kg): 2.5 mg three times daily OR 5 mg twice daily, maximum 15 mg/day 2
• More than one day of therapy is seldom necessary 2

Schizophrenia in Children (Ages 2-12)

• Starting dose: 2.5 mg two to three times daily 2
• Maximum first day: 10 mg 2
• Ages 2-5: Total daily dose usually does not exceed 20 mg 2
• Ages 6-12: Total daily dose usually does not exceed 25 mg 2

Special Populations

Elderly Patients

• Use dosages in the lower range 2
• Elderly patients are more susceptible to hypotension and neuromuscular reactions 2
• Increase dosage more gradually and monitor response carefully 2

Debilitated or Emaciated Patients

• Increase dosage more gradually 2
• Observe closely for adverse effects 2

Key Safety Considerations

Common Adverse Effects

• Sedation: Occurs in approximately 10% of patients receiving multiple doses 5
• Extrapyramidal symptoms (EPS): Occur in 4-9% of patients 5
• Prochlorperazine causes significantly less sleepiness compared to promethazine (38% versus 71%) 6

Serious Adverse Effects (Rare)

• Seizures, neuroleptic malignant syndrome, autonomic collapse, tardive dyskinesia 5
• Akathisia, pseudo-parkinsonism, dystonia 1
• Hypotension, tachycardia, arrhythmias 1

Contraindications

• CNS depression 1
• Use of adrenergic blockers 1
• Pheochromocytoma 1
• Seizure disorders 1
• GI bleeding or obstruction 1
• Children under 20 pounds or under 2 years of age 2

Clinical Pearls

Efficacy

• Prochlorperazine demonstrates superior efficacy compared to promethazine for nausea and vomiting, with faster time to complete relief (30-60 minutes) and fewer treatment failures (9.5% versus 31%) 6
• In real-world Indian practice, prochlorperazine at a mean dose of 14.9 mg/day for 7.2 days was well-tolerated with only 0.6% adverse drug reaction rate 7

Administration Considerations

• Extrapyramidal symptoms are independent of dosage in children 4
• Dystonic reactions can be immediately reversed with intramuscular orphenadrine 4
• Take particular precaution in children with acute illnesses or dehydration 2
• Tell parents not to exceed prescribed dosage, as adverse reaction risk increases with higher doses 2