Drug Card: Procainamide

Medication Name: Procainamide

  • Generic Name: Procainamide

  • Trade Name(s): Pronestyl

Drug Classification: Antiarrhythmic

Description:
Procainamide is used to treat ventricular arrhythmias and some atrial arrhythmias. It helps stabilize the cardiac membrane.

Mechanism of Action:
Procainamide works by blocking sodium channels, leading to a decrease in myocardial excitability and conduction velocity.

Pharmacokinetics:

  • Absorption: Well absorbed orally; bioavailability varies.

  • Distribution: Distributed in body tissues and fluids; crosses the placenta.

  • Metabolism: Metabolized in the liver, with active metabolites.

  • Excretion: Excreted by the kidneys; half-life is 3-4 hours.

Indications/Field Use:

  • Ventricular tachycardia (VT)

  • Atrial fibrillation

Contraindications:

  • Hypersensitivity to procainamide

  • Complete heart block

  • Systemic lupus erythematosus (SLE)

Side Effects/Adverse Reactions:

  • Hypotension

  • Arrhythmias

  • Lupus-like syndrome

Dose:

  • Loading Dose: 20 mg/min IV until arrhythmia is controlled or side effects occur (max 17 mg/kg).

  • Maintenance Infusion: 1-4 mg/min.

Precautions:

  • Monitor ECG for widening QRS.

  • Assess renal function before administration.

Drug-Drug Interactions:

  • May interact with other antiarrhythmics and increase their effects.