views updated May 29 2018


Any of a group of drugs, also termed neuroleptics, used medicinally in the therapy of schizophrenia, organic psychoses, the manic phase of manic-depressive illness, and other acute psychotic illnesses. The prototype antipsychotics are the phenothiazines, such as chlorpromazine (Thorazine), and the butyrophenones such as haloperidol (Haldol). The antipsychotics are tri-cyclic compounds, with chemical substitution at R1 and R2, which determine the selectivity and potency of the neuroleptic.

The "positive" symptoms of psychotic disorders, such as hallucinations, can often be effectively treated with antipsychotics; the "negative" symptoms, such as withdrawal, are less effectively managed by these drugs. Most of these drugs also have effects on movement, and a good response to the drugs' antipsychotic effects must often be balanced against motor side effects.


Baldessarini, R. J. (1990). Drugs and the treatment of psychiatric disorders. In A. G. Gilman et al. (Eds.), Goodman and Gilman's the pharmacological basis of therapeutics, 8th ed. New York: Peragamon.

George R. Uhl

Valina Dawson


views updated May 18 2018

antipsychotic (anti-sy-kot-ik) adj. describing one of 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), butyrophenones (e.g. haloperidol), and thioxanthenes (e.g. flupentixol). Side-effects include abnormal involuntary movements (extrapyramidal effects), sedation, dry mouth, blurred vision, and weight gain. atypical a. one of a group of antipsychotics, including clozapine, risperidone, and olanzapine (Zyprexa), that are used in treating patients unresponsive to conventional antipsychotics. Extrapyramidal side-effects are less troublesome.


views updated May 23 2018


Antipsychotic drugs (also called neuroleptic drugs) are used to treat schizophrenia and other acute psychotic illnesses. Antipsychotics include phenothiazines (such as Thorazine) and butyrophenones (such as Haldol). Some symptoms, such as hallucinations, often improve when a patient is treated with antipsychotics. However, these drugs are less effective for treating certain other symptoms, such as withdrawal (when a person avoids social contact). Side effects of these drugs may include drowsiness, slowed movements, muscle spasms, and weight gain.

see also Neuroleptic.