Comparative Pharmacology
Head-to-head clinical analysis: PROCAINAMIDE HYDROCHLORIDE versus QUINALAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROCAINAMIDE HYDROCHLORIDE versus QUINALAN.
PROCAINAMIDE HYDROCHLORIDE vs QUINALAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Class Ia antiarrhythmic agent; blocks sodium channels, slowing conduction velocity and prolonging refractory period in atrial and ventricular myocardium.
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.
Oral: 250-500 mg every 3-6 hours. IV: Loading dose 15-18 mg/kg infused over 25-30 minutes, then maintenance infusion 1-4 mg/min. Maximum total daily dose: 4 g.
10 mg orally once daily, may increase to 20 mg after 2 weeks if needed.
None Documented
None Documented
Terminal elimination half-life: 2.5-5 hours (normal renal function); prolonged to 11-20 hours in renal impairment (e.g., CrCl <30 mL/min); clinical context: requires dosing adjustment in renal failure; NAPA half-life: 6-8 hours (normal), up to 40 hours 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).
Renal: ~50-60% unchanged via glomerular filtration and tubular secretion; hepatic metabolism to N-acetylprocainamide (NAPA, active) accounts for ~15-30% of dose, further eliminated renally; biliary/fecal: negligible (<5%).
Renal: 60% unchanged; Biliary/fecal: 30% as metabolites; 10% other.
Category A/B
Category C
Antiarrhythmic (Class Ia)
Antiarrhythmic (Class Ia)