Introduction

  • Ventricular tachycardia (VT) is an uncommon but dangerous condition with an extremely variable clinical presentation.
  • Intravenous procainamide is guideline-recommended for hemodynamically stable VT (Class IIa).
  • Procainamide is an old drug with renewed evidence supporting its use, but dosing and administration strategies make it harder to use at the bedside.

Clinical Detail

ParameterDetails
Bolus dose10–17 mg/kg over 20–60 minutes (max 1 g, max rate 20–50 mg/min)
OR
100 mg every 5 minutes (max rate 50 mg/min) up to 1 g
Renal adjustmenteCrCl 10–50 mL/min: reduce dose 25–50%
eCrCl <10 mL/min: reduce dose 50–75%
Maintenance infusion1–6 mg/min
MechanismClass 1A antiarrhythmic; binds fast sodium channels (inhibiting recovery after repolarization), prolongs the action potential, and slows impulse conduction.
PK / PD
  • Onset: IV <2 min; IM 10–30 min
  • Time to peak: IV 25–60 min; IM 15–60 min
  • Duration: IV/IM 3–4 hr
  • Metabolism: hepatic to active N-acetylprocainamide (NAPA)
  • Half-life: 2.5–4.7 hr (NAPA ~7 hr); increased in renal impairment
  • Excretion: 40–70% renal, unchanged
Adverse effectsHypotension, hepatotoxicity, drug-induced lupus-like syndrome, positive ANA, sulfite-related anaphylaxis, myasthenia gravis exacerbation, angioedema.
Drug interactionsDiazepam, diltiazem, milrinone, phenytoin, hydralazine.
CompatibilityCompatible: 0.9% NaCl, 0.45% NaCl
Incompatible: D5 (variable), LR, D5NS

Clinical pearl: define institutional dosing and administration policies, given the variable strategies in the literature and the risk of adverse events.

Evidence

Author, yearDesign (n)Intervention & comparisonKey findings / outcome
Ortiz, 2017
(PROCAMIO)		RCT
n=62 analyzed of 74		IV procainamide 10 mg/kg over 20 min
vs
IV amiodarone 5 mg/kg over 20 min
  • Major cardiac adverse events: 3/33 (9%) procainamide vs 12/29 (41%) amiodarone
  • VT terminated within 40 min: 22 (67%) procainamide vs 11 (38%) amiodarone
Marill, 2010Multicenter cohort
90 patients (97 infusions)		IV amiodarone vs IV procainamideVT termination: 25% (13/53) amiodarone vs 30% (9/30) procainamide — both modestly effective, no significant difference.
Komura, 2010Retrospective
n=90		IV procainamide vs IV lidocaineProcainamide terminated 75.7% of VT vs lidocaine 35%.
Marill, 2006Case series
n=33 identified (28 evaluable)		IV amiodarone for sustained VTAmiodarone VT termination 29% (8/28 evaluable).
Gorgels, 1996Randomized
29 patients (79 = total drug injections, not patients)		IV procainamide vs IV lidocaineProcainamide terminated 79% of VT vs lidocaine 19% (p<0.001).
Callans, 1992Observational
n=15		IV procainamide (median 600 mg)VT termination 93% at a median dose of 600 mg.
Recent Evidence
deSouza, 2015Systematic reviewAntiarrhythmics for acute termination of stable monomorphic VTProcainamide, ajmaline, and sotalol were superior to lidocaine. Amiodarone was not more effective than procainamide (relative risk 4.3; confidence interval crosses 1 — consistent with non-superiority/equivalence, not evidence of procainamide superiority over amiodarone).

Conclusions

  • Procainamide is guideline-supported for stable VT (Class IIa) and, in the PROCAMIO RCT, had fewer major cardiac adverse events and higher 40-minute termination than amiodarone.
  • Empiric bolus dosing is 10–17 mg/kg up to 1 g, with renal-function-based reductions, followed by a 1–6 mg/min maintenance infusion.
  • Across the older comparative studies, termination rates are modest and variable; the best available synthesis (deSouza 2015) shows procainamide superior to lidocaine, with amiodarone not more effective than procainamide.
  • Define clear institutional protocols for dosing and administration to reduce bedside variability and adverse events.

References

  • Procainamide. Micromedex [Electronic version].Greenwood Village, CO: Truven Health Analytics. Retrieved July 6, 2020, from http://www.micromedexsolutions.com/
  • Long B, Koyfman A. Best Clinical Practice: Emergency Medicine Management of Stable Monomorphic Ventricular Tachycardia. J Emerg Med 2017;52:484-492.
  • 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. doi:10.1093/eurheartj/ehw230
  • 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. doi:10.1111/j.1553-2712.2010.00680.x
  • 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. doi:10.1253/circj.cj-09-0932
  • Marill KA, deSouza IS, Nishijima DK, Stair TO, Setnik GS, Ruskin JN. Amiodarone is poorly effective for the acute termination of ventricular tachycardia. Ann Emerg Med. 2006;47(3):217-224. doi:10.1016/j.annemergmed.2005.08.022
  • 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. doi:10.1016/s0002-9149(96)00224-x
  • 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. doi:10.1016/0735-1097(92)90060-z
  • Wellens HJ, Bär FW, Lie KI, Düren DR, Dohmen HJ. 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. doi:10.1016/0002-9149(77)90074-1
  • Recent evidence added on review (2015–2022)
  • deSouza IS, Martindale JL, Sinert R. Antidysrhythmic drug therapy for the termination of stable, monomorphic ventricular tachycardia: a systematic review. Emerg Med J. 2015;32(2):161-167. doi:10.1136/emermed-2013-202973
  • Littmann L, Olson EG, Gibbs MA. Initial evaluation and management of wide-complex tachycardia: a simplified and practical approach. Am J Emerg Med. 2019;37(7):1340-1345. doi:10.1016/j.ajem.2019.04.027
  • Regoli FD, Caputo ML, Conte G, et al. Clinical approach to hemodynamically stable wide-QRS-complex tachycardia. Front Cardiovasc Med. 2022;9:1011619. doi:10.3389/fcvm.2022.1011619
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