Examples of Antiarrhythmic Drugs
| Drug | Loading Dose | Maintenance Dose | Side Effects | Excretion |
|---|---|---|---|---|
| Class IA | ||||
| Quinidine | PO: 300-600 mg q6h | Diarrhea, tinnitus, QT prolongation, hypotension, anemia, thrombocytopenia | Hepatic | |
| Procainamide | IV: 15 mg/kg over 60 min | IV: 1-4 mg/min | Nausea, lupus-like syndrome, agranulocytosis, QT prolongation | Renal and hepatic |
| PO: 500-1000 mg q4h | ||||
| Sustained-release | PO: 1000-2500 mg q12h | |||
| Disopyramide | PO: 100-300 mg q6-8h | Myocardial depression, AV block, QT prolongation anticholinergic effects | Renal and hepatic | |
| Sustained-release | PO: 200-400 mg q12h | |||
| Class IB | ||||
| Lidocaine | IV: 1-mg/kg bolus followed by 0.5-mg/kg bolus q8-10 min to total 3 mg/kg | IV: 1-4 mg/min | Confusion, seizures, respiratory arrest | Hepatic |
| Mexiletine | PO: 150-300 mg q8-12h | Nausea, tremor, gait disturbance | Hepatic | |
| Class IC | ||||
| Flecainide | PO: 50-200 mg q12h | Nausea, exacerbation of ventricular arrhythmia, prolongation of PR and QRS intervals | Hepatic and renal | |
| Propafenone | PO: 150-300 mg q8h | Hepatic | ||
| Class II | ||||
| Metoprolol | IV: 5-10 mg q5min × 3 | PO: 25-100 mg q6h | Bradycardia, AV block, CHF, bronchospasm | Hepatic |
| Esmolol | IV: 500 µg/kg over 1 min | IV: 50 (µg/kg)/min | ||
| Class III | ||||
| Amiodarone | PO: 800-1600 mg qd × 1-2 weeks, then 400-600 mg/d × 3 weeks | PO: 100-400 mg qd | Thyroid abnormalities, pulmonary fibrosis, transaminitis, bluish skin | Hepatic |
| IV: 150 mg over 10 min | IV: 1 mg/min × 6 h, then 0.5 mg/min | |||
| Ibutilide | IV (≥60 kg): 1 mg over 10 min, can repeat after 10 min | — | Torsade de pointes, hypotension, nausea | Hepatic |
| Dofetilide | PO: 125-500 µg bid | Torsade de pointes, headache, dizziness | Renal | |
| Sotalol | PO: 80-160 mg q12h | Fatigue, bradycardia, exacerbation of ventricular arrhythmia | Renal | |
| Dronedarone | PO: 400 mg q12h | Bradycardia, AV block, prolonged QT, exacerbation of heart failure, GI discomfort | Hepatic | |
| Class IV | ||||
| Verapamil | IV: 2.5-10 mg over 3-5 min | IV: 2.5-10 mg/h | AV block, CHF, hypotension, constipation | Hepatic |
| PO: 80-120 mg q6-8 h | ||||
| Diltiazem | IV: 0.25 mg/kg over 3-5 min (maximum 20 mg) | IV: 5-15 mg/h | Hepatic | |
| PO: 30-60 mg q6h | ||||
| Other | ||||
| Digoxin | IV, PO: 0.75-1.5 mg over 24 h | IV, PO: 0.125-0.25 mg qd | Nausea, AV block, ventricular and supraventricular arrhythmias | Renal |
| Adenosine | IV: 6-mg rapid bolus; if no effect then 12-mg bolus | — | Transient hypotension or atrial standstill | — |