For lidocaine used in adult ALS with V-tach/VF or wide complex tachycardia with pulses, what is the initial dose and maximum total dose?

• A. 2 mg/kg initial; maximum 4 mg/kg
• B. 1.5 mg/kg initial; maximum 3 mg/kg
• C. 0.75 mg/kg initial; maximum 2 mg/kg
• D. 3 mg/kg initial; maximum 6 mg/kg

Answer: (B)

Lidocaine dosing for adult ventricular arrhythmias is weight-based and capped to prevent toxicity. The recommended initial bolus is 1.5 mg/kg given IV or IO. If the rhythm recurs, you may repeat with 0.5–0.75 mg/kg every 5–10 minutes, but total cumulative dose should not exceed 3 mg/kg. That makes the initial 1.5 mg/kg and the maximum total 3 mg/kg the correct pairing.

Higher initial doses or a total limit like 4–6 mg/kg would raise the risk of lidocaine toxicity, while too small an initial dose (e.g., 0.75 mg/kg) may be ineffective in the acute setting. For a typical 70 kg adult, this corresponds to about 105 mg initial and up to ~210 mg total.