Adult Dosing
Ventricular arrhythmias
Less threatening arrhythmias
- Initial daily dose: 50 mg/kg IM divided q3-6 hrs, until oral therapy can be initiated
Arrhythmias associated with anesthesia or surgery
Serious arrhythmias
- Bolus injections: 100 mg IV q5 minutes done slowly at a rate not to exceed 50 mg/minute, until the arrhythmia is suppressed or until 500 mg dose is reached
- Alt: Loading infusion containing 20 mg/mL IV infusion, administered at a rate of 1 mL/minute for 25-30 minutes (equals 500-600 mg of procainamide)
- Max advisable dose to be given either by repeated bolus injections or loading infusion is 1000 mg
- Maintenance dose
- 2 mg/mL IV infusion administered at a rate of 1-3 mL/minute
- If daily total fluid intake must be limited, administer a 4 mg/mL IV infusion at a rate of 0.5-1.5 mL/minute (equals 2-6 mg/minute)
- Note: The maintenance dose should be individualized as per age, renal elimination, hepatic acetylation rate, and cardiac status
Supraventricular arrhythmias [Not FDA approved]
- Bolus injections: 100 mg IV q5 minutes done slowly at a rate not to exceed 50 mg/min, until the arrhythmia is suppressed or until 500 mg dose is reached
- Alt: Loading infusion containing 20 mg/mL IV infusion, administered at a rate of 1 mL/minute for 25-30 minutes (equals 500-600 mg of procainamide)
- Max advisable dose to be given either by repeated bolus injections or loading infusion is 1000 mg
- Maintenance dose
- 2 mg/mL IV infusion administered at a rate of 1-3 mL/minute
- If daily total fluid intake must be limited, administer a 4 mg/mL IV infusion at a rate of 0.5-1.5 mL/minute (equals 2-6 mg/minute)
- Note: The maintenance dose should be individualized as per age, renal elimination, hepatic acetylation rate, and cardiac status
Pediatric Dosing
- Safety and effectiveness in pediatric patients have not been established
[Outline]
- Positive anti-nuclear antibody (ANA) test may develop with prolonged administration of procainamide with or without symptoms of lupus erythematosus-like syndrome. If a positive ANA titer develops, evaluate risk-benefit ratio of continued procainamide therapy [US Black Box Warning]
- Procainamide use should be reserved for treatment of life-threatening ventricular arrhythmias and is not indicated for other types of arrhythmias [US Black Box Warning]
- Serious, and sometimes fatal, hematological abnormalities including agranulocytosis, bone marrow depression, neutropenia, hypoplastic anemia and thrombocytopenia have been reported in patients receiving procainamide. Therapy should be promptly discontinued if any signs of hematologic disorders occur [US Black Box Warning]
- Procainamide should be used cautiously in arrhythmias associated with digitalis intoxication, as it may cause additional depression of conduction resulting in ventricular asystole or fibrillation
- Caution is advised and dose reduction is recommended if patient develops first degree heart block during therapy. If the block persists after dose reduction, risk-benefit ratio must be evaluated in order to continue therapy
- Predigitalization is recommended in patients with atrial flutter or fibrillation prior to procainamide administration to avoid augmentation of A-V conduction, which may result in ventricular rate acceleration beyond tolerable limits
- Caution is advised in patients with CHF, acute ischemic heart disease or cardiomyopathy, due to the risk of reduction in cardiac output even with slight depression of myocardial contractility
- Concomitant use of other group 1A antiarrhythmics may produce enhanced prolongation of conduction or depression of contractility and hypotension, particularly in patients with cardiac decompensation. Such use should only be restricted for patients with serious arrhythmias unresponsive to a single drug
- Renal insufficiency may cause increased plasma levels of procainamide with serious effects similar to those of overdosage, unless dose adjustment is done
- Procainamide may worsen symptoms of myasthenia gravis, which could be hazardous. Avoid use in patients with myasthenia gravis
- Procainamide injection contains sodium metabisulfite, which may cause allergic-type reactions including anaphylactic symptoms and life-threatening asthmatic episodes in patients having sulfite sensitivity
- Rapid administration of procainamide may cause hypotension. Monitor blood pressure with the patient supine during IV administration. Temporarily discontinue administration if blood pressure falls 15 mm Hg or more
- ECG monitoring is recommended during treatment to check therapeutic response and to detect any tendency to excessive widening of the QRS complex, prolongation of the P-R interval, or any signs of heart block
- Procainamide should be administered in hospitals having appropriate monitoring and supportive care facilities
Cautions: Use cautiously in
- Myelosuppression
- Renal impairment
- Hepatic impairment
- Asthma
- Sensitivity to other local anesthetics
- Elderly patients
Pregnancy Category:C
Breastfeeding: Limited information indicates that low levels of procainamide and its metabolites are excreted in human milk which is not expected to cause any adverse effects in breastfed infants, particularly if the infant is >2 months. Exclusively breastfed infants should be carefully monitored if this drug is used during lactation, including assessment of serum levels to rule out toxicity. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 08 June 2011). As per manufacturer's data, because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, analyzing the importance of the drug to the mother.
