Indications for: Thioridazine

Schizophrenia unresponsive to (preferably 2) other antipsychotic drugs.

Adult Dosage:

Initially 50–100mg three times daily; may increase gradually to max 800mg/day in 2–4 divided doses.

Children Dosage:

Initially 0.5mg/kg per day in divided doses; may increase gradually to max 3mg/kg per day.

Thioridazine Contraindications:

History of arrhythmias. Congenital long QT syndrome. QTc interval >450msec. Concomitant drugs that prolong QTc interval, CYP2D6 inhibitors (eg, fluoxetine within past 5 weeks, paroxetine), or others that inhibit thioridazine metabolism (eg, duloxetine, fluvoxamine, propranolol, pindolol). Reduced CYP2D6 activity. Coma. CNS or bone marrow depression. Severe hyper- or hypotensive heart disease.

Thioridazine Warnings/Precautions:

Discontinue if QTc interval >500msec occurs. Obtain ECG and K+ levels at baseline, then periodically (esp. after changing dose). Evaluate cardiac function if syncope, dizziness, palpitations, or other symptoms of torsade de pointes occurs. Bradycardia. Hypokalemia (correct K+ before starting). History of breast cancer. Seizure disorders. Monitor blood, liver and visual function. Neonates: risk of extrapyramidal and/or withdrawal symptoms post delivery (due to exposure during 3rd-trimester pregnancy). Pregnancy. Nursing mothers.

Thioridazine Classification:

Piperidine phenothiazine.

Thioridazine Interactions:

See Contraindications. QTc interval prolongation with CYP2D6 inhibitors (eg, fluoxetine, paroxetine) or inhibitors of thioridazine metabolism (eg, duloxetine, fluvoxamine, propranolol, pindolol). Potentiates CNS depression with alcohol, other CNS depressants. Potentiates atropine, organophosphate toxicity. Antagonizes quetiapine. May cause false (+) pregnancy test.

Adverse Reactions:

Drowsiness, other CNS effects, anticholinergic effects, QT prolongation, arrhythmias, hyperprolactinemia, amenorrhea, ejaculation inhibition, edema, tardive dyskinesia, neuroleptic malignant syndrome, blood dyscrasias, jaundice, gynecomastia, weight gain, pigmentary retinopathy, orthostatic hypotension, hyperpyrexia, paradoxical reaction.


Formerly known under the brand name Mellaril.

How Supplied:

Contact supplier.