What is the recommended lidocaine (Lidocaine) infusion dose for ventricular tachycardia (VT)?

Lidocaine Infusion Dosing for Ventricular Tachycardia

For ventricular tachycardia, the recommended lidocaine infusion dose is 20 to 50 μg/kg/min (1.4 to 3.5 mg/min in a 70 kg patient) following an initial loading dose of 1 mg/kg (not exceeding 100 mg). 1

Initial Loading Dose Protocol

• Administer an initial IV bolus of 1 mg/kg, not to exceed 100 mg 1
• Additional bolus injections of 0.5 mg/kg can be given every 8-10 minutes if necessary, to a total maximum of 4 mg/kg 1
• In cardiac arrest with VF/VT, only bolus therapy should be used (100 mg initially), which may be repeated every 2-3 minutes as needed 1

Maintenance Infusion

• Standard maintenance infusion: 20-50 μg/kg/min (1.4-3.5 mg/min in a 70 kg patient) 1
• Higher maintenance doses (40-50 μg/kg/min) may be required for patients who needed more than one bolus dose to suppress arrhythmias 1
• This dosing produces blood levels of up to 5 μg/ml, which is within the therapeutic range 1

Special Dosing Considerations

• For hemodynamically stable VT: Begin with standard loading dose followed by maintenance infusion 1
• For unstable VT: Consider immediate cardioversion first; lidocaine can be used if the patient is somewhat stable 1
• For VT resistant to defibrillation: Lidocaine is indicated as part of the treatment algorithm 1

Dose Adjustments for Special Populations

• Reduce infusion rates in:
  • Patients >70 years of age 1
  • Patients with congestive heart failure or cardiogenic shock 1
  • Patients with hepatic dysfunction (lidocaine is almost exclusively eliminated by the liver) 1
  • Patients with severe renal dysfunction 1
  • Patients with preexisting neurologic dysfunction 1

Duration and Monitoring

• The half-life of lidocaine increases after 24-48 hours of infusion 1
• Reduce the dose by 1 mg/min preferably at 12 hours but at least by 24 hours 1
• Monitor for subtherapeutic plasma concentrations at 30-120 minutes after initiation 1
• If arrhythmia recurs after 8-10 hours of steady infusion, give another 0.5 mg/kg bolus and increase the maintenance rate 1

Efficacy Considerations

• Lidocaine is less effective than amiodarone for shock-resistant VT (33% vs 91% failure rate) 2
• Response to lidocaine may be delayed in patients with chronic ventricular arrhythmias compared to acute-onset arrhythmias 3
• For sustained hemodynamically compromising VT, urgent electrical cardioversion is the primary treatment 1

Monitoring for Toxicity

• Monitor for CNS symptoms: nausea, drowsiness, perioral numbness, dizziness, confusion, slurred speech, muscle twitching, respiratory depression, double vision, tremor, altered consciousness 1
• Watch for cardiovascular effects: bradycardia, sinus arrest, hypotension 1
• Consider measuring serum levels with prolonged or high infusion rates or if neurologic status changes 1

Common Pitfalls to Avoid

• Increasing maintenance infusion without an additional bolus results in very slow increase in plasma concentration (>6 hours to reach new plateau) 1
• Prolonged lidocaine infusion (>40 hours) may increase risk of congestive heart failure 4
• Lidocaine may be ineffective in certain types of ventricular arrhythmias, particularly those associated with tricyclic antidepressant overdose 5
• Avoid prophylactic use beyond 24 hours unless specifically indicated 1, 4