Thorazine (chlorpromazine hydrochloride) is a first-generation antipsychotic medication widely utilized in clinical psychiatry and acute medical settings. As a phenothiazine derivative, it functions primarily by blocking dopamine receptors in the brain, thereby mitigating symptoms of psychosis, agitation, and severe nausea. Its established efficacy, broad therapeutic applications, and extensive clinical history make it a cornerstone in managing several acute and chronic psychiatric conditions. Available in oral tablets, syrup, and injectable formulations, Thorazine offers flexibility in administration tailored to patient needs and clinical contexts.

Features

• Contains chlorpromazine hydrochloride as the active ingredient
• Available in multiple formulations: oral tablets (10 mg, 25 mg, 50 mg, 100 mg, 200 mg), syrup (25 mg/5 mL, 100 mg/5 mL), and injectable solution (25 mg/mL)
• Exhibits potent antidopaminergic, antiadrenergic, and anticholinergic properties
• FDA-approved for treatment of schizophrenia, acute psychosis, severe behavioral problems, and intractable hiccups
• Also indicated for management of nausea and vomiting, preoperative apprehension, and acute intermittent porphyria
• Onset of action: oral administration within 30–60 minutes; IM injection within 10–15 minutes

Benefits

• Effectively reduces positive symptoms of psychosis such as hallucinations, delusions, and disorganized thinking
• Provides rapid sedation and control of acute agitation or manic episodes
• Helps restore functional capacity and improves quality of life in chronic psychiatric disorders
• Offers a cost-effective treatment option with a well-understood safety profile
• Useful as an antiemetic in cases refractory to conventional treatments
• Facilitates long-term maintenance therapy with oral formulations

Common use

Thorazine is primarily prescribed for the management of schizophrenia and other psychotic disorders. It is also used off-label for severe behavioral disturbances in children and adults with developmental disabilities, though this requires careful risk-benefit evaluation. In medical contexts, it is employed to control intense nausea and vomiting, particularly when standard antiemetics prove ineffective. Its sedative properties make it valuable in calming highly agitated or violent patients in emergency settings. Additionally, it remains one of the few pharmacologic options for treating intractable hiccups.

Dosage and direction

Dosage must be individualized based on diagnosis, severity of symptoms, patient response, and tolerance. For psychosis in adults, initial oral doses typically range from 25 mg to 100 mg three times daily, which may be gradually increased to 800 mg/day in divided doses. For severe conditions, intramuscular administration of 25 mg to 50 mg may be used, repeated in 1–4 hours if necessary. Maintenance doses are often lower. Elderly or debilitated patients usually require lower initial doses. Always take with food or milk to minimize gastrointestinal upset unless directed otherwise.

Precautions

Use with caution in patients with cardiovascular disease, due to risk of hypotension and tachycardia. May lower seizure threshold; exercise caution in those with epilepsy. Can cause drowsiness; advise against driving or operating machinery until response is known. Risk of neuroleptic malignant syndrome (NMS) and tardive dyskinesia (TD) exists. Periodic monitoring of CBC and liver function tests is recommended during prolonged therapy. Avoid abrupt discontinuation to prevent withdrawal symptoms or rebound psychosis.

Contraindications

Hypersensitivity to chlorpromazine or other phenothiazines. Contraindicated in comatose states, significant CNS depression due to barbiturates, alcohol, or opioids, and in patients with bone marrow suppression. Should not be used in those with suspected or established subcortical brain damage. Avoid in patients with severe cardiac disease or history of ventricular arrhythmias.

Possible side effect

Common: drowsiness, dizziness, dry mouth, blurred vision, constipation, orthostatic hypotension. Less common: extrapyramidal symptoms (e.g., dystonia, akathisia, parkinsonism), weight gain, photosensitivity, galactorrhea. Serious: agranulocytosis, neuroleptic malignant syndrome, tardive dyskinesia, seizures, jaundice, corneal and lenticular deposits. Injectable form may cause pain at injection site.

Drug interaction

Potentiates CNS depressants including alcohol, benzodiazepines, and opioids. May enhance hypotensive effects of antihypertensives. Concurrent use with anticholinergics may increase risk of heat stroke and paralytic ileus. May diminish effects of levodopa and guanethidine. Use with epinephrine may lead to paradoxical hypotension. CYP2D6 inhibitors may increase chlorpromazine levels.

Missed dose

If a dose is missed, take it as soon as remembered unless it is nearly time for the next dose. Do not double the dose to catch up. Consistent dosing is important to maintain therapeutic effect, especially in managing chronic conditions.

Overdose

Symptoms include severe drowsiness, agitation, coma, hypotension, tachycardia, convulsions, and extrapyramidal symptoms. ECG may show prolonged QT interval. Treatment is supportive and symptomatic; there is no specific antidote. Gastric lavage may be considered if ingestion was recent. Maintain airway and administer IV fluids for hypotension. Avoid epinephrine. Dialysis is not effective.

Storage

Store at room temperature (15–30°C or 59–86°F) in a tightly closed container, protected from light. Keep away from moisture. Do not freeze. Oral liquid formulations should be dispensed in amber bottles. Keep out of reach of children and pets.

Disclaimer

This information is for educational purposes and does not replace professional medical advice. Always consult a healthcare provider for diagnosis, treatment decisions, and personalized dosage recommendations. Do not initiate or discontinue Thorazine without medical supervision.

Reviews

“Thorazine has been a lifesaver for managing my son’s acute psychotic episodes. The injectable form works rapidly during crises.” — Caregiver, 52

“As a psychiatrist with 30 years of experience, I still find chlorpromazine invaluable for treatment-resistant agitation and psychosis, despite newer alternatives.” — Dr. A. Reynolds, MD

“Effective for nausea in palliative care when other drugs fail, though sedation can be pronounced.” — Oncology Nurse, 44