A 55-year-old man in the ICU develops pulseless ventricular tachycardia. After three failed defibrillation attempts, the MOST appropriate drug to administer is:

• A Lidocaine 1.5 mg/kg IV bolus
• B Magnesium sulphate 1–2 g IV over 1–2 minutes
• C Atropine 1 mg IV
• D Amiodarone 300 mg IV bolus ✓

Explanation

Amiodarone 300 mg IV bolus is the first-line antiarrhythmic drug for shock-refractory ventricular fibrillation or pulseless VT in the ACLS algorithm (2020 AHA guidelines). It is administered after the third defibrillation attempt alongside continued CPR. A second dose of 150 mg may be given for recurrent or refractory VF/VT. Lidocaine is an acceptable alternative if amiodarone is unavailable. Atropine has no role in shockable rhythms. Magnesium sulphate is reserved for torsades de pointes.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.