indication

For the treatment or relief of nausea and vomiting.

pharmacology

Thiethylperazine, an atypical antipsychotic agent, is used to treat both negative and positive symptoms of schizophrenia, acute mania with bipolar disorder, agitation, and psychotic symptoms in dementia. Future uses may include the treatment of obsessive-compulsive disorder and severe behavioral disorders in autism. Structurally and pharmacologically similar to clozapine, Thiethylperazine binds to alpha(1), dopamine, histamine H1, muscarinic, and serotonin type 2 (5-HT2) receptors.

mechanism of action

Thiethylperazine is an antagonist at types 1, 2, and 4 dopamine receptors, 5-HT receptor types 2A and 2C, muscarinic receptors 1 through 5, alpha(1)-receptors, and histamine H1-receptors. Thiethylperazine's antipsychotic effect is due to antagonism at dopamine and serotonin type 2 receptors, with greater activity at serotonin 5-HT2 receptors than at dopamine type-2 receptors. This may explain the lack of extrapyramidal effects. Thiethylperazine does not appear to block dopamine within the tubero-infundibular tract, explaining the lower incidence of hyperprolactinemia than with typical antipsychotic agents or risperidone. Antagonism at muscarinic receptors, H1-receptors, and alpha(1)-receptors also occurs with thiethylperazine.

toxicity

Manifestations of acute overdosage of TORECAN (thiethylperazine) can be expected to reflect the CNS effects of the drug and include extrapyramidal symptoms (E.P.S), confusion and convulsions with reduced or absent reflexes, respiratory depression and hypotension.

route of elimination

Thiethylperazine is eliminated in the urine.

drug interactions

Bromocriptine: The phenothiazine decreases the effect of bromocriptine

Cisapride: Increased risk of cardiotoxicity and arrhythmias

Dexfenfluramine: Decreased anorexic effect, may increase psychotic symptoms

Diethylpropion: Decreased anorexic effect, may increase psychotic symptoms

Fenfluramine: Decreased anorexic effect, may increase psychotic symptoms

Gatifloxacin: Increased risk of cardiotoxicity and arrhythmias

Grepafloxacin: Increased risk of cardiotoxicity and arrhythmias

Guanethidine: Thiethylperazine may decrease the effect of guanethidine.

Levofloxacin: Increased risk of cardiotoxicity and arrhythmias

Mazindol: Decreased anorexic effect, may increase psychotic symptoms

Phentermine: Decreased anorexic effect, may increase psychotic symptoms

Phenylpropanolamine: Decreased anorexic effect, may increase psychotic symptoms

Terfenadine: Increased risk of cardiotoxicity and arrhythmias