What is the initial lidocaine dose as an alternative antiarrhythmic in ACLS, including possible repeat dose?

• A. 0.5 mg/kg IV bolus; repeat 0.25 mg/kg
• B. 1–1.5 mg/kg IV bolus; may repeat 0.5–0.75 mg/kg
• C. 2 mg/kg IV bolus; no repeats
• D. 0.1 mg/kg IV bolus; repeat 0.05 mg/kg

Answer: (B)

Lidocaine acts as a class IB antiarrhythmic, used in ACLS as an alternative for ventricular arrhythmias when amiodarone isn’t available or appropriate. The protective approach is to give an IV bolus of 1 to 1.5 mg/kg to rapidly achieve therapeutic levels. If the rhythm recurs, you may repeat with 0.5 to 0.75 mg/kg after 5 to 10 minutes. Keep the total dose around 3 mg/kg to minimize risks of CNS or cardiovascular toxicity. If ongoing therapy is needed, an infusion of 1 to 4 mg/min can be started after the bolus. This dosing structure—initial 1–1.5 mg/kg with a smaller repeat dose—best matches how lidocaine is used in ACLS, providing a balance of effectiveness and safety.