What is the recommended dose of chlorpromazine (Thorazine) for treatment?

From the Guidelines

The recommended dose of chlorpromazine for adults is at least 600mg per day, as stated in the most recent guidelines. This dose is based on the treatment-resistant schizophrenia guidelines, which recommend a total daily dose equivalent to 600mg of chlorpromazine per day, determined using established conversion ratios 1.

• The dose may vary depending on the condition being treated and patient factors, such as age and weight.
• For adults with psychosis, the typical starting dose is 25-100 mg orally three times daily, gradually increasing to an effective dose range of 300-800 mg per day divided into multiple doses.
• For severe cases, doses may reach 1000 mg daily.
• For nausea and vomiting, lower doses of 10-25 mg every 4-6 hours are typically used.
• Elderly patients generally require lower doses, starting at about one-third to one-half the adult dose.
• Children's dosing is weight-based, usually 0.5-1 mg/kg every 4-6 hours. Chlorpromazine works by blocking dopamine receptors in the brain, which helps control psychotic symptoms and reduces nausea signals.
• Side effects include sedation, orthostatic hypotension, anticholinergic effects, and extrapyramidal symptoms.
• Dosing should be individualized based on response and tolerability, with the lowest effective dose being the goal to minimize adverse effects.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION–ADULTS Adjust dosage to individual and the severity of his condition, recognizing that the milligram for milligram potency relationship among all dosage forms has not been precisely established clinically. It is important to increase dosage until symptoms are controlled. Psychotic Disorders – Increase dosage gradually until symptoms are controlled Maximum improvement may not be seen for weeks or even months. Continue optimum dosage for 2 weeks; then gradually reduce dosage to the lowest effective maintenance level. Daily dosage of 200 mg is not unusual. Some patients require higher dosages (e.g., 800 mg daily is not uncommon in discharged mental patients). Hospitalized Patients: Acute Schizophrenic or Manic States – It is recommended that initial treatment be with chlorpromazine hydrochloride injection until patient is controlled. Usually patient becomes quiet and co-operative within 24 to 48 hours and oral doses may be substituted and increased until the patient is calm 500 mg a day is generally sufficient. While gradual increases to 2,000 mg a day or more may be necessary, there is usually little therapeutic gain to be achieved by exceeding 1,000 mg a day for extended periods.

The recommended dose of chlorpromazine (Thorazine) for treatment is:

• Psychotic Disorders: 200 mg daily, with some patients requiring higher dosages (up to 800 mg daily)
• Hospitalized Patients with Acute Schizophrenic or Manic States: 500 mg a day, with gradual increases to 2,000 mg a day or more if necessary
• Less Acutely Disturbed: 25 mg t.i.d., increased gradually until effective dose is reached (usually 400 mg daily)
• Outpatients: 10 mg t.i.d. or q.i.d., or 25 mg b.i.d. or t.i.d. 2

From the Research

Recommended Dose of Chlorpromazine

The recommended dose of chlorpromazine for the treatment of schizophrenia is not strictly defined, but several studies provide insights into the effective and safe dosage ranges.

• Low dose: ≤ 400 mg/day 3, 4
• Medium dose: 401-800 mg/day 3, 4
• High dose: > 800 mg/day 3, 4

Comparison of Dosage Groups

Studies comparing different dosage groups of chlorpromazine have reported the following findings:

• Low dose vs. medium dose: no clear benefit of one dose over the other for global and mental state outcomes, but significantly more people in the medium-dose group experienced extrapyramidal symptoms 4
• Low dose vs. high dose: clear evidence of a benefit of the high dose with regards to global state, but significantly more people in the high-dose group experienced extrapyramidal symptoms and had to leave the study due to adverse effects 3, 4

General Guidelines

While the optimal dose of chlorpromazine has been the subject of evaluative research, summaries of this work are rare, and the average dose given to people with schizophrenia has declined over time based on clinical experience rather than high-grade trial-based evidence 3, 4.

• The World Health Organization (WHO) lists chlorpromazine as one of its essential medicines for psychotic disorders 4
• Chlorpromazine is not specific for treating schizophrenia and can reduce psychosis regardless of the underlying diagnosis 5
• The dosage of chlorpromazine has changed drastically over the past 50 years, with lower doses now being the preferred choice 4