Which statement best describes the difference between typical and atypical antipsychotics, with two examples each?

• A. Typical antipsychotics primarily block dopamine receptors and have higher EPS risk; Atypical antipsychotics block dopamine and serotonin with lower EPS risk but metabolic effects.
• B. Typical antipsychotics block dopamine receptors and have lower EPS risk; Atypical antipsychotics block serotonin receptors with high EPS risk.
• C. Typical antipsychotics block serotonin receptors and have high EPS risk; Atypical antipsychotics block dopamine receptors only.
• D. Typical antipsychotics have no receptor targets; Atypical antipsychotics block both dopamine and norepinephrine.

Answer: (A)

The key idea is how receptor targets shape both efficacy and side effects. Typical antipsychotics mainly block dopamine D2 receptors in the brain, which is effective for positive psychotic symptoms but comes with a high risk of extrapyramidal symptoms such as dystonia, parkinsonism, akathisia, and long-term tardive dyskinesia. Two common examples are haloperidol and chlorpromazine, which illustrate strong D2 blockade and the corresponding EPS risk.

Atypical antipsychotics, on the other hand, block dopamine receptors as well as serotonin 5-HT2A receptors. This broader action tends to lower EPS risk and can help with negative symptoms, but it often leads to metabolic side effects like weight gain, insulin resistance, and dyslipidemia. Two typical examples are risperidone and olanzapine, which show the balance of D2 and 5-HT2A antagonism and the associated profile of side effects.