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an·ti·psy·chot·ic .ant-i-sī-'kät-ik, .an-.tī- adj of, being, or involving the use of an antipsychotic <\antipsychotic drugs>
antipsychotic n any of the powerful tranquilizers (as the phenothiazines or butyrophenones) used esp. to treat psychosis and believed to act by blocking dopamine nervous receptors called also neuroleptic
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adj.
describing a group of drugs used to treat severe mental disorders (psychoses), including schizophrenia and mania; some are administered in small doses to relieve anxiety. Formerly known as major tranquillizers, antipsychotic drugs include the phenothiazines (e.g. chlorpromazine), butyrophenone (e.g. haloperidol), and thioxanthenes (e.g. flupentixol). The atypical antipsychotics are a group of more recently developed drugs that may be helpful in those who do not respond to treatment with other antipsychotics. They include clozapine, risperidone, olanzapine (Zyprexa), and quietapine (Seroquel). Side-effects of many antipsychotics at high doses include abnormal involuntary movements.
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an·ti·psy·chot·ic (an″te-) (an″ti-si-kotґik) 1. effective in treatment of psychosis. 2. an agent for treating psychosis. Antipsychotics are a chemically diverse group (including phenothiazines, thioxanthenes, butyrophenones, dibenzoxazepines, dibenzodiazepines, dihydroindolones, and diphenylbutylpiperidines), although they are pharmacologically similar; used to treat schizophrenic, paranoid, schizoaffective, and other psychotic disorders; acute delirium and dementia and manic episodes; to control the movement disorders associated with Huntington chorea, Gilles de la Tourette syndrome, and ballismus; and to treat intractable hiccups and severe nausea and vomiting. Antipsychotic agents bind to dopamine, histamine, muscarinic cholinergic, α-adrenergic, and serotonin receptors. Blockade of dopaminergic transmission in various areas is thought to be responsible for their major effects: antipsychotic action by blockade in the mesolimbic and mesocortical areas; extrapyramidal side effects (dystonia, akathisia, parkinsonism, and tardive dyskinesia) by blockade in the basal ganglia; and antiemetic effects by blockade in the chemoreceptor trigger zone of the medulla. Sedation and autonomic side effects (orthostatic hypotension, blurred vision, dry mouth, nasal congestion, and constipation) are caused by blockade of histamine, cholinergic, and adrenergic receptors. Called also neuroleptic.Medical dictionary. 2011.