NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Which medication is known to cause irreversible tardive dyskinesia?

1. Metoclopramide

2. Prochlorperazine

3. Promethazine

4. Olanzapine

The correct answer is: Metoclopramide

Tardive dyskinesia (TD) is a movement disorder that can occur as a side effect of certain medications, particularly those used to treat mental health conditions. While all of the medications listed have been associated with TD, metoclopramide is known to be the most likely cause of irreversible TD. Prochlorperazine, promethazine, and olanzapine have been reported to cause TD, but it is generally considered to be reversible if the medication is discontinued. Therefore, it is important for healthcare providers to closely monitor patients who are taking metoclopramide for signs of TD and to consider alternative treatment options if necessary.