Thioridazine

Absorption

60%

Toxicity

LD50=956-1034 mg/kg (Orally in rats); Agitation, blurred vision, coma, confusion, constipation, difficulty breathing, dilated or constricted pupils, diminished flow of urine, dry mouth, dry skin, excessively high or low body temperature, extremely low blood pressure, fluid in the lungs, heart abnormalities, inability to urinate, intestinal blockage, nasal congestion, restlessness, sedation, seizures, shock

Description

An antipsychotic drug of the phenothiazine class. It is of particular interest because of its “atypical” properties, some of which may be due to its extensive bioconversion to active metabolites. The therapeutic and side effects of thioridazine and its metabolites involve blockade of brain dopamine receptors, but also actions mediated via blockage of muscarininc cholinergic and α-adrenergic receptors.

The Uses of Thioridazine

In terms of antipsychotic activity, thioridazine is inferior to aminazine. It is most effective in mental and emotional disorders accompanied by fear, stress, and excitement. It is prescribed for various forms of schizophrenia, psychosis, and neurosis.

Background

A phenothiazine antipsychotic used in the management of psychoses, including schizophrenia, and in the control of severely disturbed or agitated behavior. It has little antiemetic activity. Thioridazine has a higher incidence of antimuscarinic effects, but a lower incidence of extrapyramidal symptoms, than chlorpromazine. (From Martindale, The Extra Pharmacopoeia, 30th ed, p618).
Thioridazine was withdrawn worldwide in 2005 due to its association with cardiac arrythmias.

Indications

For the treatment of schizophrenia and generalized anxiety disorder.

Pharmacokinetics

Thioridazine is a trifluoro-methyl phenothiazine derivative intended for the management of schizophrenia and other psychotic disorders. Thioridazine has not been shown effective in the management of behaviorial complications in patients with mental retardation.

Metabolism

Hepatic