Introduction

Ventricular tachycardia (VT) is an uncommon but dangerous medical condition with an extremely variable clinical presentation. Intravenous procainamide is guideline recommended and is the drug of choice for hemodynamically stable VT with a class IIa recommendation. Despite being an older drug, new evidence continues to support its use, though dosing strategies and administration techniques can make it challenging to use at the bedside.

Key Concepts

  • Ventricular tachycardia is an uncommon but dangerous condition with extremely variable clinical presentation
  • Procainamide is guideline recommended as the drug of choice for hemodynamically stable VT (Class IIa)
  • Procainamide is an old drug with new evidence supporting its use in wide complex tachycardia
  • Dosing strategies and administration techniques make it difficult to use at the bedside without clear institutional protocols

Pharmacology of Procainamide

Parameter Details
Mechanism of Action
Class 1A anti-arrhythmic; blocks fast sodium channels, prolongs action potential, and reduces impulse conduction speed.
Bolus Dose

Weight-based: 10–17 mg/kg over 20–60 minutes (max dose 1 g, max rate 20–50 mg/min)

Fixed-dose: 100 mg every 5 minutes (max rate 50 mg/min) up to 1 g
Renal Adjustments

eCrCl 10–50 mL/min

Reduce dose by 25–50%

eCrCl <10 mL/min

Reduce dose by 50–75%
Maintenance Infusion
1–6 mg/min after loading dose
PK/PD
IV Onset: <2 min; IM: 10–30 min IV Peak: 25–60 min; IM: 15–60 min Duration: 3–4 hrs Metabolism: Hepatic to active NAPA Half-life: 2.5–4.7 hrs (NAPA: 7 hrs) Excretion: 40–70% renally unchanged
Adverse Effects
Hypotension Hepatotoxicity Lupus-like syndrome Positive ANA Anaphylaxis (sulfite) MG exacerbation Angioedema
Drug Interactions
Interacts with diazepam, diltiazem, milrinone, phenytoin, and hydralazine
Compatibility

Compatible: 0.9% NaCl, 0.45% NaCl

Incompatible: D5 (variable), LR, D5NS

Clinical Pearl

Define institutional dosing and administration policies due to variable strategies in the literature and risk of adverse events.

Overview of Key Evidence

Author / Year Design (n) Intervention Key Findings
Ortiz, 20173 RCT
n=62 		Procainamide vs amiodarone for stable wide QRS tachycardia (PROCAMIO study)
Procainamide: 67% VT termination 9% major cardiac adverse

Amiodarone: 38% termination, 41% adverse
Marill, 20104 Multicenter Cohort
n=187 		Amiodarone vs procainamide for sustained stable VT
Procainamide: 30% VT termination Amiodarone: 25% termination
Komura, 20105 Retrospective
n=90 		Procainamide vs lidocaine for sustained monomorphic VT
Procainamide: 75.7% VT termination Lidocaine: 35% termination
Marill, 20066 Case Series
n=33 		Amiodarone for acute termination of VT
Amio VT termination: 29% 6% needed cardioversion
Gorgels, 19967 RCT
n=79 		Procainamide vs lidocaine for sustained monomorphic VT
Procainamide: 79% VT termination Lidocaine: 19% (p<0.001)
Callans, 19928 Observational
n=15 		Procainamide infusion for VT termination
93% VT termination Median dose: 600 mg
Wellens, 19779 Observational
n=small 		Procainamide, propranolol, and verapamil effects on VT mechanism
Procainamide effective for recurrent VT

Early mechanistic evidence supporting procainamide

Clinical Conclusions

Bottom Line

Procainamide is guideline-supported and demonstrates superior VT termination rates compared to both amiodarone and lidocaine in hemodynamically stable wide complex tachycardia. Clear institutional protocols are essential for safe bedside administration.

Procainamide is guideline-supported for stable VT with a Class IIa recommendation.

Use empiric 10–17 mg/kg bolus dosing up to a maximum of 1 g.

Consider renal function for bolus dose reductions (25–50% for eCrCl 10–50 mL/min; 50–75% for eCrCl <10 mL/min).

Initiate maintenance infusion at 1–6 mg/min after the loading dose to prevent VT recurrence.

Clearly define hospital protocols to avoid variability in dosing strategies and reduce adverse event risk.

Full Reference List

  1. Procainamide. Micromedex [Electronic version]. Greenwood Village, CO: Truven Health Analytics. Retrieved July 6, 2020, from http://www.micromedexsolutions.com/
  2. Long B, Koyfman A. Best Clinical Practice: Emergency Medicine Management of Stable Monomorphic Ventricular Tachycardia. J Emerg Med. 2017;52:484-492.
  3. Ortiz M, Martín A, Arribas F, et al. Randomized comparison of intravenous procainamide vs. intravenous amiodarone for the acute treatment of tolerated wide QRS tachycardia: the PROCAMIO study. Eur Heart J. 2017;38(17):1329-1335.
  4. Marill KA, deSouza IS, Nishijima DK, et al. Amiodarone or procainamide for the termination of sustained stable ventricular tachycardia: an historical multicenter comparison. Acad Emerg Med. 2010;17(3):297-306.
  5. Komura S, Chinushi M, Furushima H, et al. Efficacy of procainamide and lidocaine in terminating sustained monomorphic ventricular tachycardia. Circ J. 2010;74(5):864-869.
  6. Marill KA, deSouza IS, Nishijima DK, et al. Amiodarone is poorly effective for the acute termination of ventricular tachycardia. Ann Emerg Med. 2006;47(3):217-224.
  7. Gorgels AP, van den Dool A, Hofs A, et al. Comparison of procainamide and lidocaine in terminating sustained monomorphic ventricular tachycardia. Am J Cardiol. 1996;78(1):43-46.
  8. Callans DJ, Marchlinski FE. Dissociation of termination and prevention of inducibility of sustained ventricular tachycardia with infusion of procainamide: evidence for distinct mechanisms. J Am Coll Cardiol. 1992;19(1):111-117.
  9. Wellens HJ, Bär FW, Lie KI, et al. Effect of procainamide, propranolol and verapamil on mechanism of tachycardia in patients with chronic recurrent ventricular tachycardia. Am J Cardiol. 1977;40(4):579-585.
Tags: Antiarrhythmic Therapy Cardiology Pharmacology Procainamide Ventricular Tachycardia Wide Complex Tachycardia

Never Miss a Pearl

Get Pharmacy Pearls delivered weekly

Join 3,000+ pharmacists who receive curated clinical insights every Friday.

Start Free Trial