From the listed drugs, which is an atypical antipsychotic?

• A. Haloperidol
• B. Clozapine
• C. Chlorpromazine
• D. Thioridazine

Answer: (B)

Atypical antipsychotics are a newer class that address both positive and negative symptoms with fewer movement-related side effects than the older typical agents. Clozapine is the classic atypical antipsychotic because it blocks both dopamine D2 receptors and serotonin 5-HT2A receptors, a combination that reduces extrapyramidal symptoms and can help with treatment-resistant or negative symptoms. In contrast, the other listed drugs are typical antipsychotics that primarily block D2 receptors and tend to produce more EPS and other motor side effects. Clozapine’s broader receptor activity explains why it’s categorized as atypical, though it requires careful monitoring for possible agranulocytosis and other serious risks.