What type of pharmacological action do second-generation antipsychotics (SGAs) primarily exhibit?

Second-generation antipsychotics (SGAs) primarily exhibit serotonin-dopamine antagonism. This characteristic is crucial because SGAs are designed to target both serotonin receptors, particularly the 5-HT2A receptor, and dopamine D2 receptors. The dual action allows for improved treatment of psychotic symptoms, such as those found in schizophrenia, while simultaneously reducing the risk of extrapyramidal side effects commonly associated with first-generation antipsychotics, which primarily focus on dopamine antagonism alone.

By blocking serotonin receptors, SGAs help to alleviate negative symptoms of schizophrenia, such as social withdrawal and cognitive deficits, which are less effectively treated by older antipsychotics. The balance between serotonin and dopamine activity contributes to a better side effect profile and greater efficacy in managing a broader range of symptoms in patients with psychotic disorders.