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Thioridazine Dosage

Medically reviewed by Last updated on April 24, 2020.

Applies to the following strengths: 30 mg/mL; 100 mg/mL; 10 mg; 25 mg; 50 mg; 100 mg; 150 mg; 200 mg; 15 mg; 25 mg/5 mL; 100 mg/5 mL

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Schizophrenia

Initial dose: 50 to 100 mg orally 3 times a day
Maintenance dose: 200 to 800 mg/day, divided into 2 to 4 doses
Maximum dose: 800 mg/day

-Once control is attained, the dose should be gradually lowered to determine the minimum effective maintenance dose.

Use: Patients with schizophrenia who failed to respond to treatment with other antipsychotic agents

Usual Pediatric Dose for Schizophrenia

Initial dose: 0.5 mg/kg/day orally, in divided doses
Maximum dose: 3 mg/kg/day, in divided doses

-The dose should be increased gradually until therapeutic effects are observed and/or the maximum dose is reached.

Use: Patients with schizophrenia who have failed to respond to treatment with other antipsychotic agents

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Dose Adjustments

Patients at risk of QT Prolongation and/or CYP450 2D6 poor metabolizers:
-QT interval greater than 450 msec at baseline: Not recommended
-QT interval greater than 500 msec during treatment: Discontinue use


-QT PROLONGATION AND SUDDEN DEATH: This drug is associated with dose-related increases in QTc prolongation, the development of Torsades de pointes arrhythmias, and sudden death. Use should be restricted to patients with schizophrenia who fail to show an acceptable response to appropriately dosed antipsychotic drugs due to insufficient effectiveness or the inability to achieve an effective dose because of intolerable side effects of the drugs.

-INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS: This drug has an increased risk of mortality when administered to elderly patients with dementia-related psychosis. Elderly patients with dementia-related psychosis treated with antipsychotic drugs have an increased risk of death. This drug is not approved for use in patients with dementia-related psychosis.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments

Administration advice:
-See manufacturer product information.

Storage requirements:
-See manufacturer product information.

-Safety and efficacy of treatment in patients for refractory schizophrenia is not known.
-Use should be limited to patients who have failed treatment with other antipsychotic drugs.
-The lowest effective dose should be used due to a dose-related risk of QT prolongation, arrhythmia, and death.

-ECGs, especially before starting treatment, during dose adjustments, and periodically thereafter
-Potassium, especially before starting treatment and periodically thereafter
-Periodic WBC with differential tests, especially in patients with signs/symptoms of infection/sore throat or with a history of low WBCs or drug-induced neutropenia/leukopenia
-Eye examinations, especially in patients on prolonged treatment
-Periodic electrolyte levels, especially in patients with a high risk of developing cardiovascular events and/or those taking diuretics

Patient advice:
-Warn patients to avoid abrupt discontinuation of this drug.
-Tell patients to immediately report any signs/symptoms of neutropenia/leukopenia, neuroleptic malignant syndrome, tardive dyskinesia, or Torsades de pointes.
-Advise patients, and families/caregivers to monitor and report signs/symptoms of unusual behavior immediately to their healthcare provider (e.g., agitation, irritability, anxiety, panic attacks, insomnia, hostility, aggressiveness, impulsivity, akathisia, hypomania/mania).
-Patients should be advised to report all concurrent prescription and nonprescription medications or herbal products they are taking.
-Patients should be instructed to speak to a healthcare provider if they are pregnant, intend to become pregnant, or are breastfeeding.
-Inform patients that this drug may cause drowsiness, and they should avoid driving or operating machinery until the full effects of the drug are seen.

Further information

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