Antipsychotic drugs have been used for over 60 years and are broadly divided into 2 groups: first-generation (“typical”) antipsychotics (FGAs) and second-generation (“atypical”) antipsychotics (SGAs) (Table 11-1). The distinction between the 2 categories is based on differences in receptor activity, adverse effects, and overall efficacy, although there is overlap in both classes. Both are used in the treatment of schizophrenia as well as in the management of bipolar disorder and other psychiatric conditions. FGAs are primarily dopamine receptor blockers, whereas SGAs inhibit both serotonin and dopamine. FGAs are more likely to cause extrapyramidal “Parkinson-like” side effects (including rigidity and tremor) and tardive dyskinesia (involuntary movements of the face, tongue, trunk, and extremities).
Table 11-1 Antipsychotic Medications
Antipsychotic medications effectively reduce many symptoms of acute and chronic psychoses, allowing more patients to function outside psychiatric institutions. In addition to potential extrapyramidal reactions, other adverse effects include drowsiness, orthostatic hypotension, anticholinergic effects, and weight gain. Less common problems include cholestatic jaundice, blood dyscrasias, photosensitivity, and a rare idiosyncratic reaction known as neuroleptic malignant syndrome (NMS). NMS is characterized by “lead-pipe” muscle rigidity and hyperthermia and can lead to rhabdomyolysis and possible death if not recognized and treated. The SGAs may be less likely to cause these adverse effects, although higher doses may still cause problems.
Excerpted from BCSC 2020-2021 series: Section 1 - Update on General Medicine. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.