procainamide
Pronunciation: proh-KANE-ah-myde
Class IA antiarrhythmic medication used to treat both atrial and ventricular arrhythmias by blocking sodium channels.
Full Definition
Procainamide is a class IA antiarrhythmic agent that works by blocking voltage-gated sodium channels in cardiac tissue, thereby slowing conduction velocity and increasing refractoriness. It is effective against both supraventricular and ventricular arrhythmias and can be administered intravenously for acute treatment or orally for chronic suppression. The drug has significant side effects including lupus-like syndrome with chronic use, hypotension during IV administration, and potential for QT prolongation leading to torsades de pointes. Its active metabolite, N-acetylprocainamide (NAPA), also possesses antiarrhythmic properties.
Usage
Usage note: Monitor for lupus-like syndrome with chronic use; distinguish from procaine.
In Context
- "Intravenous procainamide successfully terminated the sustained ventricular tachycardia without hemodynamic compromise." — Emergency department note
- "Long-term procainamide therapy was discontinued due to development of drug-induced lupus syndrome." — Cardiology follow-up note