Compazine (prochlorperazine) is a prescription medication belonging to the phenothiazine class of antipsychotics. It is primarily indicated for the management of severe nausea and vomiting, as well as for the treatment of schizophrenia and nonpsychotic anxiety. With its potent dopamine receptor antagonism, Compazine offers rapid and reliable symptom control in both acute and chronic clinical scenarios, making it a trusted choice among healthcare professionals for decades. Its well-established efficacy and safety profile support its use in hospital and outpatient settings.

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 of action: 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 to 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 gastroenteritis.
• Reduces agitation, hallucinations, and delusions in psychotic disorders such as schizophrenia.
• Offers flexible administration routes (oral, IM, IV, rectal) to accommodate patient needs and clinical situations.
• Helps manage acute nonpsychotic anxiety when other treatments are not suitable or effective.
• Supports improved quality of life and functional capacity by alleviating debilitating symptoms.
• Long-standing clinical evidence and familiarity among prescribers ensure well-understood risk-benefit profile.

Common use

Compazine is commonly used for the management of severe nausea and vomiting in various clinical contexts, including postoperative recovery, chemotherapy-induced emesis, and acute episodes of vertigo. In psychiatric practice, it is employed to treat manifestations of schizophrenia, such as thought disorder, agitation, and paranoid ideation. It is also sometimes used off-label for migraine-associated nausea and as an adjunct in the treatment of intractable hiccups. Its use is generally reserved for moderate to severe cases where first-line antiemetics or anxiolytics have proven insufficient.

Dosage and direction

Dosage must be individualized based on indication, severity, patient response, and route of administration. For severe nausea and vomiting in adults: Oral tablets—5 to 10 mg three or four times daily; extended-release capsules—10 to 30 mg twice daily; IM—5 to 10 mg every 3 to 4 hours, not to exceed 40 mg/day; IV—2.5 to 10 mg, slow injection or infusion; rectal—25 mg twice daily. For psychiatric disorders: Oral—5 to 10 mg three or four times daily; IM—10 to 20 mg every 2 to 4 hours until controlled, then switch to oral. Elderly or debilitated patients should receive lower initial doses. Always follow prescribing clinician’s instructions.

Precautions

Use with caution in patients with cardiovascular disease, glaucoma, prostate hypertrophy, or seizure disorders. May cause drowsiness or dizziness; advise against driving or operating machinery until response is known. Avoid abrupt discontinuation after long-term use. Monitor for signs of neuroleptic malignant syndrome (NMS) or tardive dyskinesia. Periodic CBC and liver function tests recommended during prolonged therapy. Not recommended during pregnancy unless potential benefit justifies potential risk. Use in pediatric patients should be carefully considered and monitored.

Contraindications

Contraindicated in patients with known hypersensitivity to prochlorperazine or other phenothiazines. Should not be used in comatose or severely depressed states, in patients with bone marrow suppression, or in those with suspected subcortical brain damage. Avoid use in pediatric patients with signs and symptoms of Reyes syndrome. Concomitant use with large doses of CNS depressants is contraindicated. Do not administer to patients with a history of blood dyscrasias.

Possible side effect

Common side effects include drowsiness, dizziness, dry mouth, blurred vision, and constipation. Less frequently, orthostatic hypotension, extrapyramidal symptoms (e.g., dystonia, akathisia, parkinsonism), and tardive dyskinesia may occur. Rare but serious adverse effects include neuroleptic malignant syndrome, agranulocytosis, and jaundice. Allergic reactions such as rash or photosensitivity are possible. Report any persistent or severe side effects to a healthcare provider promptly.

Drug interaction

May potentiate effects of CNS depressants including alcohol, barbiturates, and opioids. Concurrent use with antihypertensives may increase risk of hypotension. May diminish effects of levodopa and other dopamine agonists. CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) may increase prochlorperazine levels. Use with caution alongside other QT-prolonging agents. Antacids and antidiarrheals may reduce absorption of oral Compazine.

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 make up for a missed one. If regular dosing is essential (e.g., in psychiatric maintenance), maintain schedule as closely as possible. Consult prescriber for specific guidance based on indication and dosage regimen.

Overdose

Symptoms of overdose may include severe drowsiness, coma, hypotension, tachycardia, extrapyramidal symptoms, agitation, restlessness, convulsions, and ECG changes. Management is supportive and symptomatic; there is no specific antidote. Gastric lavage may be considered if ingestion was recent. Maintain airway and cardiovascular support. Avoid epinephrine in treatment of hypotension due to risk of paradoxical further decrease in blood pressure. Contact poison control immediately.

Storage

Store at room temperature (15–30°C or 59–86°F) in a tight, light-resistant container. Keep away from moisture and heat. Do not freeze liquid forms. Keep all medications out of reach of children and pets. Do not use beyond the expiration date printed on the packaging.

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 decades of use support Compazine’s efficacy in controlling severe nausea, vomiting, and psychotic symptoms. Many healthcare providers value its rapid onset and multiple formulation options, particularly in emergency or inpatient settings. Some patients report significant symptom relief, though side effects such as sedation or extrapyramidal symptoms are noted considerations. Overall, it remains a relevant option in specific clinical scenarios where its benefits outweigh potential risks.