From the Guidelines
No, amiodarone should not be held in a patient who has experienced ventricular fibrillation (v-fib). Amiodarone is a critical antiarrhythmic medication that helps prevent recurrence of life-threatening ventricular arrhythmias like v-fib. According to the 2015 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1, amiodarone should be considered if episodes of VT or VF are frequent and can no longer be controlled by successive electrical cardioversion or defibrillation.
After an episode of v-fib, amiodarone is typically continued or initiated at a loading dose of 150 mg IV over 10 minutes, followed by an infusion of 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours. Maintenance therapy is usually 200-400 mg orally once daily. Discontinuing amiodarone could significantly increase the risk of recurrent v-fib, which can be fatal. Amiodarone works by blocking potassium channels, prolonging the action potential and refractory period in cardiac tissue, which helps prevent the chaotic electrical activity that characterizes v-fib.
Some key points to consider when using amiodarone in patients with v-fib include:
- Regular monitoring of thyroid, liver, and pulmonary function is recommended during long-term therapy
- Amiodarone has potential side effects including thyroid dysfunction, pulmonary toxicity, and liver abnormalities, but these risks are generally outweighed by the benefit of preventing recurrent v-fib in the acute setting
- The 2006 ACC/AHA/ESC guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death also support the use of amiodarone in patients with LV dysfunction due to prior MI and symptoms due to VT unresponsive to beta-adrenergic blocking agents 2.
However, the most recent and highest quality study, the 2015 ESC guidelines 1, takes precedence in guiding clinical decision-making. Therefore, amiodarone should not be held in a patient who has experienced v-fib, and its use should be continued or initiated as part of the management strategy to prevent recurrent life-threatening ventricular arrhythmias.
From the FDA Drug Label
Amiodarone HCl injection is indicated for initiation of treatment and prophylaxis of frequently recurring ventricular fibrillation and hemodynamically unstable ventricular tachycardia in patients refractory to other therapy. The answer is no, we do not hold amiodarone in a patient who has had an episode of v-fib, as it is indicated for treatment and prophylaxis of ventricular fibrillation. 3
From the Research
Amiodarone Therapy in Patients with V-Fib
- Amiodarone is an effective antiarrhythmic medication used to treat ventricular arrhythmias, including ventricular fibrillation (V-Fib) 4.
- The medication has a complex pharmacokinetic profile and can cause various side effects, including thyroid dysfunction, pulmonary fibrosis, and hepatic injury, which require regular monitoring 5, 6.
- In patients who have experienced an episode of V-Fib, amiodarone can be used to prevent recurrent ventricular arrhythmias, but its use should be carefully monitored due to the risk of side effects 7, 4.
Considerations for Holding Amiodarone
- There is no clear evidence to suggest that amiodarone should be held in patients who have had an episode of V-Fib, but the medication's potential side effects and interactions should be carefully considered 5, 6.
- In some cases, amiodarone may need to be discontinued or dose-adjusted due to severe side effects, such as thyroid dysfunction or pulmonary toxicity 7, 8.
- The decision to hold or continue amiodarone therapy should be made on a case-by-case basis, taking into account the individual patient's medical history, current condition, and potential risks and benefits of the medication 4, 6.