A 34-year-old woman with schizophrenia has a baseline QTc of 480 ms with recurrent torsades documented on telemetry. Her psychosis requires an antipsychotic. Which agent should be avoided most strongly?
- A Haloperidol
- B Lurasidone
- C Ziprasidone ✓
- D Aripiprazole
Correct answer: C. Ziprasidone
Explanation
Among commonly used antipsychotics, thioridazine and ziprasidone produce the greatest degree of QT prolongation. Ziprasidone blocks hERG potassium channels and should be avoided in patients with known long QT or prior torsades. Lurasidone and aripiprazole have among the lowest QT liabilities, and haloperidol produces modest prolongation compared to ziprasidone. Hypokalaemia and concurrent QT-prolonging drugs amplify the risk with any agent chosen.
Reference: Katzung Basic and Clinical Pharmacology, 16th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.