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Compazine Dosage

Dosage form: tablet, film coated
Drug classes: Phenothiazine antiemetics, Phenothiazine antipsychotics

Medically reviewed by Last updated on Feb 2, 2024.


(For children’s dosage and administration, see below.) Dosage should be increased more gradually in debilitated or emaciated patients.

Elderly Patients

In general, dosages in the lower range are sufficient for most elderly patients. Since they appear to be more susceptible to hypotension and neuromuscular reactions, such patients should be observed closely. Dosage should be tailored to the individual, response carefully monitored and dosage adjusted accordingly. Dosage should be increased more gradually in elderly patients.

To Control Severe Nausea and Vomiting

Adjust dosage to the response of the individual. Begin with the lowest recommended dosage.

Oral Dosage - Tablets

Usually one 5 mg or 10 mg tablet 3 or 4 times daily. Daily dosages above 40 mg should be used only in resistant cases.

In Adult Psychiatric Disorders

Adjust dosage to the response of the individual and according to the severity of the condition. Begin with the lowest recommended dose. Although response ordinarily is seen within a day or 2, longer treatment is usually required before maximal improvement is seen.

Oral Dosage

Non-Psychotic Anxiety – Usual dosage is 5 mg 3 or 4 times daily. Do not administer in doses of more than 20 mg per day or for longer than 12 weeks.

Psychotic Disorders including Schizophrenia – In relatively mild conditions, as seen in private psychiatric practice or in outpatient clinics, dosage is 5 or 10 mg 3 or 4 times daily.

In moderate to severe conditions, for hospitalized or adequately supervised patients, usual starting dosage is 10 mg 3 or 4 times daily. Increase dosage gradually until symptoms are controlled or side effects become bothersome. When dosage is increased by small increments every 2 or 3 days, side effects either do not occur or are easily controlled. Some patients respond satisfactorily on 50 to 75 mg daily.

In more severe disturbances, optimum dosage is usually 100 to 150 mg daily.


Do not use in pediatric surgery.

Children seem more prone to develop extrapyramidal reactions, even on moderate doses. Therefore, use lowest effective dosage. Tell parents not to exceed prescribed dosage, since the possibility of adverse reactions increases as dosage rises.

Occasionally the patient may react to the drug with signs of restlessness and excitement; if this occurs, do not administer additional doses. Take particular precaution in administering the drug to children with acute illnesses or dehydration (see under Dystonia).

Severe Nausea and Vomiting in Children

COMPAZINE® (prochlorperazine maleate tablets USP) should not be used in pediatric patients under 20 pounds in weight or 2 years of age. It should not be used in conditions for which children’s dosages have not been established. Dosage and frequency of administration should be adjusted according to the severity of the symptoms and the response of the patient. The duration of activity following intramuscular administration may last up to 12 hours. Subsequent doses may be given by the same route if necessary.

Oral Dosage

More than 1 day’s therapy is seldom necessary.

Weight Usual Dosage Not to Exceed
under 20 lbs not recommended
20 to 29 lbs 2.5 mg 1 or 2 times a day 7.5 mg per day
30 to 39 lbs 2.5 mg 2 or 3 times a day 10 mg per day
40 to 85 lbs 2.5 mg 3 times a day or 5 mg 2 times a day 15 mg per day

In Children With Schizophrenia

Oral Dosage

For children 2 to 12 years, starting dosage is 2.5 mg 2 or 3 times daily. Do not give more than 10 mg the first day. Then increase dosage according to patient’s response.

FOR AGES 2 to 5, total daily dosage usually does not exceed 20 mg.

FOR AGES 6 to 12, total daily dosage usually does not exceed 25 mg.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.