Can lidocaine and amiodarone be given together?

Lidocaine and Amiodarone Can Be Given Together in Cardiac Arrest

Yes, lidocaine and amiodarone can be administered together during cardiac arrest management, though this combination is not typically first-line therapy and should be considered only after individual agents have failed.

Evidence for Combined Use

The American Heart Association (AHA) guidelines acknowledge that both amiodarone and lidocaine can be used for ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) that is unresponsive to defibrillation 1. While the guidelines don't explicitly recommend routine combined use, they do suggest that if the first antiarrhythmic fails, switching to the alternative agent may be considered 1.

Individual Agent Efficacy

• Amiodarone: Initial dose 300 mg IV/IO, with a second dose of 150 mg if required 1
• Lidocaine: Initial dose 1.0-1.5 mg/kg IV/IO, with additional doses of 0.5-0.75 mg/kg (maximum 3 mg/kg) 1

Amiodarone has been shown to increase short-term survival to hospital admission compared to placebo or lidocaine in patients with refractory VF 2, 3. In one study, survival to hospital admission was 22.8% with amiodarone versus 12.0% with lidocaine 3.

However, more recent evidence from a 2023 study suggests that lidocaine may be associated with better outcomes for in-hospital cardiac arrest, showing higher rates of return of spontaneous circulation, 24-hour survival, survival to discharge, and favorable neurologic outcomes compared to amiodarone 4.

Sequential vs. Combined Use

The typical approach is sequential rather than simultaneous administration:

1. Try amiodarone first (300 mg IV/IO)
2. If ineffective, consider lidocaine (1-1.5 mg/kg IV/IO)
3. Consider the alternative agent if the first fails 1

Precautions When Using Together

When administering both medications, be aware of:

• Potential for additive effects: Both drugs can cause myocardial depression and hypotension
• Monitoring requirements: Close cardiac monitoring is essential
• Dosing adjustments: Consider reduced doses of each when used in combination

The AHA guidelines specifically note that "sinus bradycardia has been reported with oral amiodarone in combination with lidocaine given for local anesthesia" 5, suggesting potential interaction concerns.

Special Considerations

• Formulation matters: The polysorbate-based amiodarone formulation is preferred during cardiac arrest but may cause more hypotension 1
• Avoid simultaneous administration: Give medications sequentially rather than simultaneously to monitor for adverse effects
• Post-ROSC management: After return of spontaneous circulation, carefully monitor for hypotension and bradycardia if both agents are continued

Conclusion

While lidocaine and amiodarone can be administered together in refractory cardiac arrest scenarios, the evidence suggests that sequential use is more common in clinical practice. The decision to use both should be based on the patient's response to individual agents and the specific clinical context.