8 known interactions • 3 major • 5 moderate • 0 minor
Always disclose all medications to your healthcare providers — prescription medicines, OTC medications, vitamins, and herbal supplements. This list may not include every possible interaction. Use our Medicine Interaction Checker to screen your complete medication list.
Potentially life-threatening or causing permanent damage. Avoid combination.
May worsen condition or require dose adjustment. Monitor closely.
Usually limited clinical effect. Manage with routine monitoring.
amiodarone
Amiodarone raises procainamide and NAPA plasma concentrations and adds to QT prolongation, increasing the risk of torsades de pointes. Reduce procainamide dose and monitor levels and the ECG closely if used together.
sotalol
Additive QT-interval prolongation markedly increases the risk of torsades de pointes and other ventricular proarrhythmia. Concurrent use of two QT-prolonging antiarrhythmics is generally avoided.
quinidine
Combining two Class IA agents produces additive sodium-channel blockade and QT prolongation, with excessive QRS widening and proarrhythmia. This combination should be avoided.
cimetidine
Cimetidine inhibits renal tubular secretion of procainamide and NAPA, raising their plasma levels and the risk of toxicity. Monitor levels and consider dose reduction or an alternative acid-suppressing agent.
trimethoprim
Trimethoprim competes for renal tubular secretion, increasing procainamide and NAPA concentrations. Monitor for QT prolongation and signs of toxicity.
metoprolol
Beta-blockers add to the negative inotropic and conduction-slowing effects of procainamide, increasing the risk of bradycardia, hypotension, and heart block. Monitor heart rate, blood pressure, and conduction.
digoxin
Both drugs affect cardiac conduction; combined use can increase the risk of bradyarrhythmias and conduction disturbances, particularly in patients with underlying nodal disease.
ondansetron
Co-administration with other QT-prolonging drugs such as ondansetron compounds the risk of QT prolongation and torsades de pointes. Use with ECG monitoring and avoid in patients with baseline QT prolongation.
Always ask your pharmacist about potential interactions with food, alcohol, and supplements specific to Procainamide. Some medicines have significant interactions with grapefruit juice, high-fat meals, dairy products, or vitamin K-rich foods.