Comparative Pharmacology
Head-to-head clinical analysis: PROCAINAMIDE HCL versus QUINALAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROCAINAMIDE HCL versus QUINALAN.
PROCAINAMIDE HCL vs QUINALAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Class Ia antiarrhythmic agent; blocks sodium channels, decreases phase 0 slope of action potential, prolongs refractory period, and increases action potential duration.
Quinidine (the active ingredient in Quinalan) is a class Ia antiarrhythmic agent that binds to and blocks voltage-gated sodium channels in cardiac myocytes, prolonging the action potential duration and effective refractory period. It also has vagolytic effects and blocks potassium channels.
For life-threatening ventricular arrhythmias, IV: Loading dose: 100 mg administered at a rate of 25-50 mg/min, may repeat every 5 minutes until arrhythmia suppressed or up to a total of 500-1000 mg. Maintenance: IV infusion 1-4 mg/min. Oral: 250-500 mg every 3-6 hours; maximum 4 g/day.
10 mg orally once daily, may increase to 20 mg after 2 weeks if needed.
None Documented
None Documented
Terminal elimination half-life: 2.5-4.7 hours (3 hours typical) in normal renal function; prolonged to 11-20 hours in renal impairment; NAPA half-life 6-8 hours (prolonged in renal failure).
Terminal half-life: 12 hours (range 10-14) in normal renal function; prolonged to 24-30 hours in severe renal impairment (CrCl <30 mL/min).
Primarily renal (50-60% unchanged via glomerular filtration and tubular secretion) with 10-30% as N-acetylprocainamide (NAPA) metabolite; minor biliary/fecal (<5%).
Renal: 60% unchanged; Biliary/fecal: 30% as metabolites; 10% other.
Category A/B
Category C
Antiarrhythmic (Class Ia)
Antiarrhythmic (Class Ia)