What is the recommended loading dose and infusion rate for amiodarone (antiarrhythmic medication) in the management of atrial fibrillation with rapid ventricular response (AFib RVR)?

From the Guidelines

For atrial fibrillation with rapid ventricular response (AFib RVR), the recommended amiodarone regimen consists of a 150 mg IV loading dose administered over 10 minutes, followed by a 1 mg/min infusion for 6 hours (360 mg), and then a 0.5 mg/min maintenance infusion for the remaining 18 hours (540 mg). This typically amounts to a total dose of 1050 mg over 24 hours 1. The loading dose should be diluted in 100 mL of D5W, while the infusion should be prepared in a more dilute concentration. Amiodarone works by blocking multiple ion channels (sodium, potassium, and calcium) and has noncompetitive beta-blocking effects, which helps control ventricular rate and potentially convert AFib to normal sinus rhythm.

Some key points to consider when administering amiodarone for AFib RVR include:

• Close monitoring is essential during administration due to potential hypotension, bradycardia, and QT interval prolongation 1.
• For patients with severe hemodynamic compromise, a higher loading dose of 300 mg IV may be considered 1.
• Liver and thyroid function should be monitored with prolonged use, as amiodarone can cause hepatotoxicity and thyroid dysfunction 1.
• The efficacy and safety of amiodarone in controlling heart rate and converting AFib to normal sinus rhythm have been established in various studies, including those published in the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines 1.

Overall, the use of amiodarone for AFib RVR is supported by strong evidence, and its administration should be guided by established protocols and close monitoring to minimize potential adverse effects.

From the FDA Drug Label

The recommended starting dose of amiodarone is about 1000 mg over the first 24 hours of therapy, delivered by the following infusion regimen:

• Initial Load: 150 mg in 100 mL (in D5W) infused over 10 minutes
• Followed by: 1 mg/min for 6 hours
• Followed by: 0.5 mg/min thereafter

The recommended loading dose for amiodarone in the management of atrial fibrillation with rapid ventricular response (AFib RVR) is 150 mg infused over 10 minutes. The recommended infusion rate is:

• 1 mg/min for the first 6 hours
• 0.5 mg/min thereafter 2. Key points to consider:
• The dose may be individualized for each patient
• Mean daily doses above 2100 mg were associated with an increased risk of hypotension
• Do not exceed an initial infusion rate of 30 mg/min 2 2

From the Research

Amiodarone Drip and Loading for AFib RVR

• The recommended loading dose and infusion rate for amiodarone in the management of atrial fibrillation with rapid ventricular response (AFib RVR) is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
• However, the studies suggest that amiodarone is one of the commonly used medications for rate control in AFib RVR, but its effectiveness and safety compared to other medications such as metoprolol and diltiazem are still being researched 5.
• A study published in 2017 found that metoprolol had a lower failure rate than amiodarone in achieving rate control in AFib RVR, but the initial agent used was not associated with in-hospital mortality 5.
• Another study published in 2022 discussed the importance of rate control in AFib RVR, but did not provide specific guidelines for amiodarone dosing 6.
• A study published in 2022 also discussed the acute management of AFib in congestive heart failure with reduced ejection fraction, but focused on the use of calcium channel blockers and beta blockers, rather than amiodarone 7.
• The 1994 study mentioned that intravenous beta blockers and calcium channel blockers are equally effective in rapidly controlling the ventricular rate in acute AF, but did not provide information on amiodarone dosing 4.

Key Findings

• Amiodarone is used for rate control in AFib RVR, but its effectiveness and safety compared to other medications are still being researched 5.
• Metoprolol had a lower failure rate than amiodarone in achieving rate control in AFib RVR 5.
• The choice of medication for rate control in AFib RVR should be based on individual patient factors and clinical context 3, 4, 6, 7.