Generic Name

Prochlorperazine Maleate

---

Classification

FDA Approved Indications

• Nausea and vomiting
• Psychotic disorders (e.g., schizophrenia)

Mechanism of Action

Blocks dopamine receptors in the brain, particularly in the chemoreceptor trigger zone (CTZ), reducing nausea and psychotic symptoms.

Dosage and Administration

Adult: Typically 5-10 mg three to four times daily, adjusted based on response.

Pediatric: Dose varies; generally 0.15 mg/kg/day divided into 3-4 doses, not to exceed 40 mg/day.

Geriatric: Start at lower doses due to increased sensitivity; monitor closely.

Renal Impairment: Use with caution; dose adjustments may be necessary.

Hepatic Impairment: Use with caution; monitor for increased sedation or EPS.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses the blood-brain barrier.

Metabolism: Primarily hepatic via the cytochrome P450 system.

Excretion: Renal and biliary excretion.

Half Life: Approximately 10-19 hours.

Contraindications

• Comatose states
• Bone marrow suppression
• Hypersensitivity to phenothiazines

Precautions

• Sedation, EPS, anticholinergic effects, hypotension
• Use cautiously in elderly, Parkinson's disease, cardiac disorders, and in those with a history of seizure disorder

Adverse Reactions - Common

• Drowsiness, dizziness, dry mouth (Common)
• Extrapyramidal symptoms (EPS) (Common)
• Dizziness, orthostatic hypotension (Common)

Adverse Reactions - Serious

• Tardive dyskinesia (Serious and potentially irreversible)
• Neuroleptic malignant syndrome (NMS) (Rare)
• QT prolongation and arrhythmias (Rare)

Drug-Drug Interactions

• Other CNS depressants, antihypertensives, drugs that prolong QT interval

Drug-Food Interactions

• Alcohol potentiates sedative effects

Drug-Herb Interactions

• St. John's Wort may increase risk of CNS side effects

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed.
• Report any involuntary movements, fever, muscle rigidity.
• Avoid alcohol and CNS depressants.
• Caution when operating machinery due to sedation.

Special Considerations

Black Box Warnings:

• Increased risk of death in elderly patients with dementia-related psychosis

Genetic Factors: Slow metabolizers may have increased plasma levels leading to enhanced effects and side effects.

Lab Test Interference: May cause false-positive in some diagnostic tests of catecholamine levels.

Overdose Management

Signs/Symptoms: Sedation, hypotension, EPS, coma.

Treatment: Supportive care, activated charcoal if recent ingestion, monitor vital signs, manage symptoms; possibly use diphenhydramine for EPS.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable for 2-3 years if stored properly.