Compazine (prochlorperazine) is a prescription phenothiazine antipsychotic and antiemetic agent used for the management of severe nausea and vomiting, as well as for the control of manifestations of psychotic disorders. It functions primarily by blocking dopamine receptors in the chemoreceptor trigger zone (CTZ) of the brain, thereby reducing the sensation of nausea and mitigating psychotic symptoms. Its efficacy is well-documented in clinical settings, making it a trusted option for physicians managing acute and severe gastrointestinal and psychiatric presentations. Proper medical supervision is essential due to its potent effects and potential side effect profile.

Features

• Active ingredient: Prochlorperazine
• Available forms: Tablets (5 mg, 10 mg), extended-release capsules (10 mg, 15 mg, 30 mg), injection (5 mg/mL), suppositories (2.5 mg, 5 mg, 25 mg)
• Mechanism: Dopamine D2 receptor antagonist
• Onset of action: Oral—30 to 40 minutes; IM—10 to 20 minutes; IV—rapid; rectal—60 minutes
• Half-life: Approximately 6–8 hours
• Metabolism: Hepatic, via CYP450 enzymes
• Excretion: Primarily renal

Benefits

• Provides rapid and effective control of severe nausea and vomiting, including that induced by chemotherapy, surgery, or vertigo.
• Helps manage acute psychotic episodes, reducing agitation, hallucinations, and delusions in conditions such as schizophrenia.
• Offers multiple administration routes (oral, IM, IV, rectal), allowing flexibility in clinical and emergency settings.
• Can be used as a supportive therapy in migraine-associated nausea.
• Demonstrates reliable antiemetic and antipsychotic efficacy with a well-understood pharmacological profile.
• May reduce the need for adjunctive medications in complex symptom management.

Common use

Compazine is commonly prescribed for the management of severe nausea and vomiting, including postoperative nausea, nausea associated with cancer chemotherapy, and severe vertigo. It is also indicated for the control of severe, nonchronic psychotic disorders, such as acute exacerbations of schizophrenia. Off-label uses may include adjunctive treatment in migraine headaches and management of acute anxiety or agitation in emergency settings, though these are not primary indications.

Dosage and direction

Dosage must be individualized based on indication, severity of symptoms, patient response, and route of administration.

• For severe nausea/vomiting:
  • Adults: Oral: 5–10 mg 3–4 times daily; IM: 5–10 mg every 3–4 hours as needed; IV: 2.5–10 mg, may repeat once if necessary; Max: 40 mg/day.
  • Children (≥2 years, ≥20 lb): Oral: 0.4 mg/kg/24 hr divided in 3–4 doses; IM: 0.1–0.15 mg/kg/dose.
• For psychosis:
  • Adults: Oral: 5–10 mg 3–4 times daily; IM: 10–20 mg every 2–4 hours; Max: 200 mg/day.
  • Elderly/debilitated patients: Use lower initial doses.
    Administer with food or milk to minimize gastrointestinal upset. Avoid abrupt discontinuation.

Precautions

• May cause drowsiness, dizziness, or blurred vision; patients should avoid driving or operating machinery until response is known.
• Use with caution in patients with cardiovascular disease, glaucoma, seizures, or Parkinson’s disease.
• May cause orthostatic hypotension; advise patients to rise slowly from sitting/lying positions.
• Risk of neuroleptic malignant syndrome (NMS) and tardive dyskinesia (TD); monitor for symptoms.
• Not recommended for children under 2 years or weighing less than 20 lb.
• Elderly patients with dementia-related psychosis treated with antipsychotics are at an increased risk of death.

Contraindications

• Hypersensitivity to prochlorperazine or other phenothiazines.
• Comatose or severely depressed states (e.g., CNS depression due to alcohol, barbiturates, opioids).
• Bone marrow suppression.
• Pediatric patients with signs/symptoms of Reye’s syndrome.
• Avoid in patients with suspected or established subcortical brain damage.

Possible side effect

Common side effects may include drowsiness, dizziness, dry mouth, blurred vision, constipation, and orthostatic hypotension. Less commonly, extrapyramidal symptoms (e.g., dystonia, akathisia, parkinsonism) may occur. Rare but serious adverse effects include neuroleptic malignant syndrome, tardive dyskinesia, agranulocytosis, and seizures. Allergic reactions, including rash and photosensitivity, may also occur.

Drug interaction

• May enhance CNS depression when used with alcohol, sedatives, hypnotics, or opioids.
• Anticholinergic agents may increase risk of adverse effects.
• May reduce the effectiveness of levodopa and other dopamine agonists.
• Concurrent use with antihypertensives may potentiate hypotension.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) may increase prochlorperazine levels.
• Use cautiously with QT-prolonging agents due to potential additive effects.

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next dose. Do not double the dose to catch up. Resume the regular dosing schedule. If uncertain, contact a healthcare provider for guidance.

Overdose

Symptoms of overdose may include severe drowsiness, agitation, coma, hypotension, tachycardia, extrapyramidal symptoms, seizures, and respiratory depression. Management is supportive and symptomatic; there is no specific antidote. Activated charcoal may be considered if ingestion was recent. Seek immediate medical attention; contact a poison control center.

Storage

Store at room temperature (20–25°C or 68–77°F), away from light, moisture, and heat. Keep all medications out of reach of children and pets. Do not flush medications down the toilet or pour into drainage unless instructed to do so.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Do not disregard professional medical advice or delay in seeking it because of something you have read here.

Reviews

Clinical studies and patient reports generally support the efficacy of Compazine in managing severe nausea and psychotic symptoms. Many healthcare professionals value its rapid onset and versatility in formulation. However, side effects, particularly extrapyramidal symptoms, are frequently noted. Patient experiences vary; some report significant symptom relief, while others discontinue use due to adverse effects. Always consult a healthcare provider for personalized advice.