Classification: antiarrhythmic
  • useful in supraventricular and ventricular tachycardias
  • may be useful when lidocaine is ineffective 
  • undergoes hepatic metabolism to active metabolite, N-acetyl-procainamide (NAPA)
  • Bolus:
    • 100mg IV direct q5 minutes to a maximum of 1 g then maintenance infusion 2 - 6mg/min
    • 17mg/kg IV direct as loading dose followed by maintenance infusion 2.8mg/kg/hr
  • dose must be reduced in renal failure to maintenance infusion 1.4mg/kg/hr
  • IV Direct:
    • administration rate should not exceed 25-50 mg/min
  • IV Infusion:
    • 2g/500mL D5W or NS
  • yellow discoloration is acceptable; dark amber solutions should be discarded
Adverse Effects:
  • Cardiac:
    • arrhythmias: ventricular tachycardia or fibrillation, Torsades de Pointes (associated with high levels of procainamide and/or NAPA; secondary to prolonged QT interval)
    • heart block
    • prolongation of PR, QRS, QT intervals (up to 50%)
    • bradycardia, asystole
    • decreased BP, decreased CO
  • Immunologic:
    • lupus erythematosus like syndrome
    • fever
    • neutropenia, agranulocytosis, thrombocytopenia
  • Others:
    • peripheral neuropathy
  • myasthenia gravis
  • in complete heart block or type II second degree heart block unless functional pacemaker in place (can suppress a ventricular escape rhythm)
  • following electrical conversion
Drug Interactions:
  • procainamide + amiodarone = increased plasma procainamide concentration
  • procainamide + cimetidine = increased plasma procainamide concentration
  • procainamide + lidocaine = increased CNS toxicity
  • procainamide + neuromuscular blockers = increased neuromuscular blockade
Monitoring Therapy:
  • ECG (PR, QRS, QT widening by 50%)
  • BP
  • cardiac index 
  • CBC, platelets
  • procainamide serum level: therapeutic: 17-68 uM/L (pre-dose)
  • procainamide + NAPA serum level:  therapeutic: 43-128 uM/L (pre-dose)
CCTC Protocol:
  • May be administered by IV infusion by an RN.
  • May be titrated by an approved nurse in the CCTC.

Lynne Kelly, Pharmacist, CCTC
Brenda Morgan, Clinical Nurse Specialist, CCTC
Last Update: August 7, 2006

LHSCHealth Professionals

Last Updated March 24, 2009 | © 2007, LHSC, London Ontario Canada