Vaughan Williams Antiarrhythmic Classification
The Vaughan Williams classification of antiarrhythmic drug actions, the classic grouping by primary electrophysiologic mechanism, classes Ia/Ib/Ic/II/III/IV.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Vaughan Williams class
- III - K-channel blocker (amiodarone, sotalol, dofetilide)
Result: Vaughan Williams class III: potassium-channel blockers (prolong repolarization) - amiodarone, sotalol, dofetilide.
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What the result means
- Class Ia
- Sodium-channel blockers, moderate block (quinidine, procainamide, disopyramide).
- Class Ib
- Sodium-channel blockers, weak block (lidocaine, mexiletine).
- Class Ic
- Sodium-channel blockers, marked block (flecainide, propafenone).
- Class II
- Beta-adrenergic blockers (metoprolol, propranolol, esmolol).
- Class III
- Potassium-channel blockers (amiodarone, sotalol, dofetilide, ibutilide).
- Class IV
- Non-dihydropyridine calcium-channel blockers (verapamil, diltiazem).
What you enter
- Vaughan Williams class
How this is calculated
Vaughan Williams EM. A classification of antiarrhythmic actions reassessed after a decade of new drugs. J Clin Pharmacol. 1984;24(4):129-147. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.