A 24-year-old man started on haloperidol develops syncope. ECG shows a QTc of 520 msec with runs of polymorphic ventricular tachycardia. Which antipsychotic is the most appropriate alternative if dopamine blockade is still required but QT risk must be minimized?

• A Thioridazine
• B Ziprasidone
• C Amisulpride
• D Haloperidol switched to oral route ✓

Explanation

Among antipsychotics, thioridazine, ziprasidone, amisulpride, and IV haloperidol carry the greatest QT prolongation risk, so none of these is acceptable here. Oral haloperidol at standard doses has substantially less QT effect than the intravenous formulation, and switching route while correcting electrolytes (potassium and magnesium) addresses the arrhythmia risk while preserving D2 blockade. Aripiprazole is another low-QT option if a class change is desired.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.