What is the recommended dosage of Prochlorperazine (antiemetic and antipsychotic medication) for treating nausea and vomiting, and for psychiatric conditions?

Prochlorperazine Dosing Recommendations

For nausea and vomiting, prochlorperazine should be dosed at 10 mg orally every 4-6 hours as needed, with a maximum daily dose of 40 mg; for psychiatric conditions including schizophrenia, start with 5-10 mg orally 3-4 times daily and titrate to 100-150 mg daily for severe cases. 1

Antiemetic Use (Nausea and Vomiting)

Standard Dosing for Adults

• Oral tablets: 5-10 mg orally 3-4 times daily 1
• Maximum daily dose: 40 mg per day for resistant cases 1
• Alternative dosing: 10 mg every 4-6 hours as needed 2
• Rectal suppository: 25 mg every 12 hours 2
• Intravenous route: 2.5-5 mg IV push over one minute provides rapid relief (mean time to cessation of vomiting 8.5 minutes) 3

Context-Specific Applications

Chemotherapy-induced nausea (low to moderate emetogenic risk):

• 10 mg orally pretreatment (optional) 2
• 10 mg orally every 6 hours as needed for breakthrough symptoms 2
• Can be given intravenously at similar doses if oral route unavailable 2

Opioid-induced nausea prevention:

• 5 mg orally twice daily when initiating oxycodone reduces nausea incidence to 18.1% 4
• 10-15 mg/day orally for prevention, though carries 14% risk of extrapyramidal symptoms (specifically akathisia within one week) 5

Emergency department acute vomiting:

• 2.5 mg IV push initially; repeat once after 20 minutes if no response 3
• 10 mg IV provides superior efficacy compared to promethazine (9.5% vs 31% treatment failure rate) 6

Pediatric Dosing (≥2 years and ≥20 lbs)

Weight-based dosing for nausea/vomiting 1:

• 20-29 lbs: 2.5 mg 1-2 times daily (max 7.5 mg/day)
• 30-39 lbs: 2.5 mg 2-3 times daily (max 10 mg/day)
• 40-85 lbs: 2.5 mg 3 times daily or 5 mg twice daily (max 15 mg/day)
• Duration: More than one day's therapy seldom necessary 1

Psychiatric Use

Non-Psychotic Anxiety

• Dose: 5 mg orally 3-4 times daily 1
• Maximum: Do not exceed 20 mg per day 1
• Duration: Do not use longer than 12 weeks 1

Schizophrenia and Psychotic Disorders

Mild conditions (outpatient):

• Start: 5-10 mg orally 3-4 times daily 1

Moderate to severe conditions (hospitalized patients):

• Start: 10 mg orally 3-4 times daily 1
• Increase gradually by small increments every 2-3 days 1
• Target range: 50-75 mg daily for satisfactory response 1
• Optimal dose for severe disturbances: 100-150 mg daily 1

Pediatric schizophrenia (ages 2-12):

• Start: 2.5 mg 2-3 times daily 1
• Maximum first day: 10 mg 1
• Ages 2-5: Total daily dose usually does not exceed 20 mg 1
• Ages 6-12: Total daily dose usually does not exceed 25 mg 1

Special Populations and Precautions

Elderly Patients

• Use lower dosage ranges 1
• More susceptible to hypotension and neuromuscular reactions 1
• Titrate more gradually and monitor closely 1

Critical Safety Considerations

Extrapyramidal symptoms:

• Occur in 14% of patients receiving 10-15 mg/day for antiemetic purposes 5
• Akathisia typically appears within one week 5
• Children are more prone to extrapyramidal reactions even on moderate doses 1
• Use lowest effective dosage in pediatric patients 1

Contraindications in children:

• Do not use in pediatric surgery 1
• Avoid in children with acute illnesses or dehydration (increased dystonia risk) 1
• Do not use if child shows restlessness or excitement 1

Bioavailability advantage:

• Buccal administration produces plasma concentrations more than twice as high as oral tablets with less than half the variability 7
• Exposure to metabolites is approximately half that of oral tablets 7

Comparative efficacy:

• Superior to promethazine for ED nausea/vomiting with faster complete relief and fewer treatment failures 6
• Causes significantly less sleepiness than promethazine (38% vs 71%) 6