Antipsychotic medications have efficacy in the treatment of acute psychosis (irrespective of cause), chronic psychotic disorders, and other psychiatric conditions.
First-generation antipsychotics (FGAs), also known as neuroleptics or conventional antipsychotics, cause extrapyramidal side effects, including rigidity, bradykinesia, tremor, and akathisia (restlessness). They also frequently lead to tardive dyskinesia—hyperkinetic, involuntary movements most readily observed in the face and extremities.
Second-generation antipsychotics (SGAs), also known as atypical antipsychotics, generally have lower risks of extrapyramidal side effects and tardive dyskinesia compared to FGAs. However, these medications generally cause higher rates of weight gain and metabolic side effects, although the side effect profiles of individual drugs vary. One SGA, clozapine, has sufficiently unique properties to justify separate consideration.
The pharmacology, administration, and comparative side effects of second-generation antipsychotics available in the US are discussed here. First-generation antipsychotics and antipsychotics in the treatment of schizophrenia and bipolar disorder are discussed separately, as are antipsychotic poisoning, tardive dyskinesia, and neuroleptic malignant syndrome (See "Pharmacotherapy for schizophrenia: Acute and maintenance phase treatment" and "Pharmacotherapy for schizophrenia: Side effect management" and "First generation (Typical) antipsychotic medication poisoning" and "Second generation (atypical) antipsychotic medication poisoning" and "Neuroleptic malignant syndrome" and "Tardive dyskinesia: Etiology and epidemiology" and "Bipolar disorder in adults: Pharmacotherapy for acute mania and hypomania" and "Guidelines for prescribing clozapine in schizophrenia".)
Second-generation antipsychotic medications are also referred to as “atypical antipsychotics”. First-generation antipsychotics may be referred to as “conventional antipsychotics” or “neuroleptics”. The older term "major tranquilizer" does not accurately describe the action of these medications, and is no longer encouraged.