From the Guidelines
The maintenance dose of amiodarone should be 100-200 mg QD. This dose is recommended to minimize long-term adverse effects, as stated in the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1.
Key Considerations
- The maintenance dose may vary depending on the patient's response and the specific arrhythmia being treated.
- Amiodarone has a long half-life, allowing for once-daily dosing, but also requiring regular monitoring of liver function, thyroid function, and pulmonary status due to potential toxicities.
- Dose adjustments may be necessary based on clinical response, side effects, and drug interactions, as amiodarone inhibits multiple cytochrome P450 enzymes and can increase levels of many medications.
Potential Adverse Effects
- Bradycardia, QT prolongation, torsades de pointes, gastrointestinal upset, constipation, hypothyroidism, hyperthyroidism, pulmonary fibrosis, hepatic toxicity, corneal deposits, optic neuritis, peripheral neuropathy, photosensitivity, and adult respiratory distress syndrome.
Precautions and Interactions
- Sinus or AV conduction disease, inflammatory lung disease, hepatic dysfunction, hypothyroidism, hyperthyroidism, peripheral neuropathy, abnormal gait/ataxia, optic neuritis, and drugs with SA and/or AV nodal–blocking properties.
- Amiodarone is a substrate of and inhibits P-glycoprotein and CYP2C9, CYP2D6, and CYP3A4, and is an inhibitor of OCT2.
- Reduce warfarin dose by 50%, and reduce digoxin dose by 30%–50% when co-administered with amiodarone 1.
From the FDA Drug Label
The recommended starting dose of amiodarone HCl injection is about 1000 mg over the first 24 hours of therapy, delivered by the following infusion regimen: After the first 24 hours, the maintenance infusion rate of 0. 5 mg/min (720 mg/24 hours) should be continued
- The maintenance dose of amiodarone is 0.5 mg/min, which is equivalent to 720 mg/24 hours 2
From the Research
Maintenance Dose of Amiodarone
The maintenance dose of amiodarone varies, but several studies provide guidance on the typical dosage range.
- A study from 1983 3 found that the dose was reduced from 572 +/- 283 mg per day to 372 +/- 174 mg per day at 6 months due to frequent side effects.
- A 2010 study 4 recommends keeping the maintenance dose at 200 to 300 mg/day to decrease side effects.
- A 2017 study 5 suggests that lower amiodarone maintenance doses (100-200 mg/day) are preferred, and high-dose maintenance regimens (daily dose ≥300 mg) are usually obsolete.
- Other studies from 1984 6 and 1983 7 used maintenance doses ranging from 100 to 800 mg/day, with a median dose of 300 mg/day.
Factors Influencing Maintenance Dose
The maintenance dose of amiodarone may be influenced by several factors, including: