If epinephrine is ineffective after two administrations, which medications should be considered?

• A. Magnesium sulfate
• B. Defibrillate immediately
• C. Lidocaine or Amiodarone
• D. Calcium chloride bolus

Answer: (C)

When a shockable rhythm like VF/VT persists after two doses of epinephrine, the next pharmacologic step is an antiarrhythmic to stabilize the heart and improve the chance of ROSC. Lidocaine or amiodarone serve this role by reducing abnormal electrical activity and helping convert/refrain the rhythm. Magnesium is targeted for torsades de pointes or low magnesium, not as a generic next step after epinephrine in this scenario. Calcium chloride is reserved for specific electrolyte disturbances or certain poisonings, not routinely after epinephrine in cardiac arrest. Defibrillation should continue as indicated by the rhythm, but the medications to consider specifically at this point are lidocaine or amiodarone. In practice, amiodarone is usually preferred, with lidocaine as an alternative if needed.