Indication	Administration route and setting	Dosage	Potential adverse effects
Life-threatening arrhythmia	IV, inpatient treatment	150-mg IV bolus over 10 minutes (if necessary, bolus may be repeated in 10 to 30 minutes); then 1 mg per minute for 6 hours; then 0.5 mg per minute for 18 hours; then reduce IV dosage or convert to oral dosing when possible.2	Hypotension, bradycardia, atrioventricular block
Ventricular arrhythmia	Oral, inpatient treatment	800 to 1,600 mg per day in divided doses until a total of 10 g has been given; then 200 to 400 mg per day.2	Bradycardia, QT prolongation, GI upset, constipation; rarely, torsades de pointes
Atrial fibrillation	Oral, inpatient or outpatient treatment	600 to 800 mg per day in divided doses until a total of 10 g has been given (may use higher initial dosage or IV dosing in unstable inpatients); then 200 mg per day10	Bradycardia, QT prolongation, GI upset, constipation; rarely, torsades de pointes