- Life-Threatening Ventricular Arrhythmia (e.g. Ventricular Tachycardia)
- Disopyramide is rarely indicated (other options preferred)
-
Atrial Fibrillation Rhythm Control (maintain sinus rhythm)
- Proarrhythmic
- Consider starting while in hospital on telemetry monitoring
- Higher mortality in structural heart disease (Systolic Dysfunction, Myocardial Infarction)
- Similar to other Class 1A anti-arrhythmics (e.g. Quinidine, Procainamide)
- Class 1A anti-arrhythmic
- Blocks the fast Sodium channel in cardiac cell membranes within atrial and ventricular tissues
- Slows the rate and amplitude of phase 0 depolarization
- Prolongs the Action Potential (decreases cell excitability and conduction velocity)
- Cardiac depressant
- Directly decreases the rate of phase 4, diastolic cell depolarization and automaticity
-
Potassium Channel Blocker
- Prolongs QT Interval
- Increases refractory period
- Potent Anticholinergic activity
- May increase AV Node conduction
- Considered safe in Lactation
- Pregnancy Category C
- Of ingested medication, 50% is hepatic metabolized and 50% is excreted unchanged
- Precautions
- Start 6 hours after last dose of Class 1A anti-arrhythmics (e.g. Quinidine, Procainamide)
- Wait 6 hours before giving first XR formulation after transitioning from immediate Disopyramide
- Ventricular Arrhythmia
- Disopyramide 400 to 800 mg orally divided every 6 hours (immediate release) or 12 hours (XR)
-
Atrial Fibrillation Rhythm Control (maintain sinus rhythm)
- Disopyramide 400 to 750 mg orally divided every 6 hours (immediate release) or 12 hours (XR)
- Renal Impairment
- Creatinine Clearance 40 to 60 ml/min: 400 mg/day in divided doses
- Creatinine Clearance 30 to 40 ml/min: 100 mg every 8 hours
- Creatinine Clearance 15 to 30 ml/min: 100 mg every 12 hours
- Creatinine Clearance <15 ml/min: 100 mg every 24 hours
- Other maximum dosing (use immediate release products for these conditions)
- Indications to limit dose to 400 mg/day in divided doses
- Significant liver disease
- Indications to limit dose to 100 mg/day divided every 6 to 8 hours
- Cardiomyopathy
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 74-5
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
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