Dosage Forms. Tablet: 100 mg, 200 mg, 300 mg, and 400 mg
Common FDA Label Indication, Dosing and Titration.
1. Ventricular arrhythmia, treatment and prophylaxis: 800-1600 mg po daily in divided doses for 1-3 wk, titrate down to 600-800 mg po daily for 1 mo, then to maintenance dose of 400-600 mg po daily given as single dose or divided bid
1. Atrial fibrillation, prophylaxis after open heart surgery: 600-1200 mg po daily in divided doses, started post-op and continued until hospital discharge
2. Supraventricular arrhythmia: 600-1200 mg po daily for 1-2 wk, tapered to 400-600 mg po daily for 1-3 wk, then to maintenance dose of 200 mg po daily
MOA. Type III antiarrhythmic that prolongs the effective refractory period of atrial and ventricular tissue by blocking potassium conductance
Drug Characteristics: Amiodarone
Medication Safety Issues: Amiodarone
Drug Interactions: Amiodarone
Adverse Reactions: Amiodarone
Efficacy Monitoring Parameters. ECG for normalized sinus rhythm.
Toxicity Monitoring Parameters. ECG for QT prolongation; eye examinations at baseline and every 6 mo; chest x-ray and pulmonary function tests every 3-6 mo; liver enzymes; thyroid function tests.
Key Patient Counseling Points. Use sunscreen, avoid tanning beds. Report signs/symptoms of cardiac arrhythmias, pulmonary toxicity, or liver toxicity. Take consistently with regard to meals but avoid taking with grapefruit or grapefruit juice. Avoid sudden discontinuation.
Clinical Pearls. May exacerbate arrhythmias. Loading dose is given in the hospital, and a response requires at least 1 wk, usually two or more. May cause skin to turn bluish-grey in color, known as “smurf syndrome.”