For tardive dyskinesia, which antipsychotic is preferred to switch to?

• A. Haloperidol
• B. Clozapine
• C. Risperidone
• D. Olanzapine

Answer: (B)

Tardive dyskinesia comes from long-term blockade of dopamine D2 receptors in the motor pathways, so the goal is to switch to an antipsychotic with the lowest risk of extrapyramidal effects. Clozapine stands out because it has the lowest propensity for EPS and tardive symptoms among antipsychotics, thanks to its pharmacology of weaker D2 antagonism in the nigrostriatal pathway and stronger 5-HT2A antagonism. Switching to clozapine can reduce ongoing motor side effects and may even improve TD in some patients. Of course, clozapine requires regular blood monitoring due to the risk of agranulocytosis and other potential side effects. Other antipsychotics in these options carry higher risks of movement disorders, especially haloperidol, which makes clozapine the preferred choice for TD.