Antiarrhythmics (Vaughan-Williams IA)
- Moderate Na+ block + K+ channel block
- Slow conduction and prolong repolarization
- Quinidine/procainamide/disopyramide
- QRS and QT can both widen
- Torsades + proarrhythmia are major limits
- Mostly niche/specialist drugs now
Class at a glance
- Moderate Na+ block + K+ channel block
Members / distinctions
- Slow conduction and prolong repolarization
- Quinidine/procainamide/disopyramide
Safety / monitoring
- QRS and QT can both widen
Other member distinctions
- Torsades + proarrhythmia are major limits
- Mostly niche/specialist drugs now
Self-check
- How does Antiarrhythmics (Vaughan-Williams IA) work?
Moderate Na+ block + K+ channel block. - Which ECG intervals can both widen with class IA antiarrhythmics?
QRS and QT.
Drugs in this class (6)
Antiarrhythmics (Vaughan-Williams IA) prescription history
Animated chart of estimated U.S. prescriptions per year, Antiarrhythmics (class I/III) (1930–2026). Class IA highlighted from 1930.
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