Describing an Atypical Antipsychotic: Receptor Binding and Its Role in Pathophysiology

All antipsychotics have actions at dopamine-2 receptors, but the atypical agents behave differently than the conventional antipsychotics at those receptors. In addition, the atypical antipsychotics block serotonin-2 receptors. These differences in receptor-binding profiles provide the basis for 2 theories that explain why the 2 classes of antipsychotics are similar in efficacy but different in side effect profile, especially in their propensity to cause motor side effects such as extrapyramidal symptoms and tardive dyskinesia.