Is there a benefit to using amiodarone (antiarrhythmic medication) and lidocaine (local anesthetic and antiarrhythmic medication) in the management of ventricular fibrillation (V fib) arrest?

From the Guidelines

Amiodarone and lidocaine can be beneficial in managing ventricular fibrillation (V fib) arrest, but they are considered second-line treatments after defibrillation and high-quality CPR. The most recent and highest quality study, published in 2018 1, suggests that both amiodarone and lidocaine may be considered for shock-refractory VF/pVT, with amiodarone generally preferred as the first antiarrhythmic agent.

Key Points

• Amiodarone is typically administered at 300 mg IV push for the first dose, followed by 150 mg if needed, as recommended by the 2010 American Heart Association guidelines 1.
• Lidocaine can be used as an alternative at 1-1.5 mg/kg IV initially, with a second dose of 0.5-0.75 mg/kg if necessary, as stated in the 2010 guidelines 1.
• Neither medication should delay defibrillation attempts or compromise chest compressions, and they are most effective when given early in cardiac arrest, ideally within the first few minutes.
• For patients with refractory V fib not responding to initial treatments, using both medications sequentially may be considered, though evidence for this combined approach is limited.
• Addressing underlying causes of the arrest, such as electrolyte abnormalities, ischemia, or toxins, remains crucial for successful resuscitation.

Medication Administration

• Amiodarone: 300 mg IV push for the first dose, followed by 150 mg if needed.
• Lidocaine: 1-1.5 mg/kg IV initially, with a second dose of 0.5-0.75 mg/kg if necessary. It is essential to note that the optimal sequence of ACLS interventions for VF/pVT cardiac arrest, including administration of a vasopressor or antiarrhythmic drug, and the timing of medication administration in relation to shock delivery are not known, as stated in the 2018 guidelines update 1.

From the FDA Drug Label

Amiodarone hydrochloride injection is indicated for initiation of treatment and prophylaxis of frequently recurring ventricular fibrillation (VF) and hemodynamically unstable ventricular tachycardia (VT) in patients refractory to other therapy. There is a benefit to using amiodarone in the management of ventricular fibrillation (V fib) arrest, as it is indicated for the initiation of treatment and prophylaxis of frequently recurring V fib. However, the label does not provide direct information about the benefit of using lidocaine in combination with amiodarone for V fib arrest. Therefore, the benefit of using lidocaine in this context cannot be determined from the provided label information 2.

From the Research

Benefits of Amiodarone and Lidocaine Infusion in V Fib Arrest

• The use of amiodarone and lidocaine in the management of ventricular fibrillation (V fib) arrest has been studied in several trials 3, 4, 5, 6, 7.
• A study published in the New England Journal of Medicine in 2002 found that amiodarone leads to substantially higher rates of survival to hospital admission in patients with shock-resistant out-of-hospital ventricular fibrillation compared to lidocaine 3.
• Another study published in the American Journal of Cardiology in 1983 found that amiodarone is highly effective in the long-term treatment of ventricular tachycardia or ventricular fibrillation refractory to conventional antiarrhythmic drugs, but causes significant toxicity in approximately 50% of patients 4.
• A review of the literature published in Interactive Cardiovascular and Thoracic Surgery in 2008 recommended the use of amiodarone as the first-line drug in patients with refractory ventricular arrhythmias after cardiac surgery, with lidocaine as an alternative if amiodarone is not available or contraindicated 5.
• However, a randomized trial published in the New England Journal of Medicine in 2016 found that neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia 6.
• A nationwide database study published in Cardiovascular Drugs and Therapy in 2016 also found no significant difference in the rate of survival to hospital discharge between cardiogenic out-of-hospital cardiac arrest patients with persistent ventricular fibrillation on hospital arrival treated with amiodarone or lidocaine 7.

Comparison of Amiodarone and Lidocaine

• The available evidence suggests that amiodarone may be more effective than lidocaine in certain situations, such as in patients with shock-resistant out-of-hospital ventricular fibrillation 3.
• However, other studies have found no significant difference in outcomes between amiodarone and lidocaine 6, 7.
• The choice of antiarrhythmic medication may depend on individual patient factors, such as the presence of underlying heart disease or other comorbidities.

Clinical Implications

• The use of amiodarone and lidocaine in the management of V fib arrest should be guided by current clinical guidelines and the individual patient's circumstances 5.
• Further research is needed to determine the optimal treatment strategy for patients with V fib arrest and to identify predictors of response to antiarrhythmic medication.