Comparative Pharmacology
Head-to-head clinical analysis: DISOPYRAMIDE PHOSPHATE versus QUINALAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DISOPYRAMIDE PHOSPHATE versus QUINALAN.
DISOPYRAMIDE PHOSPHATE vs QUINALAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Class Ia antiarrhythmic agent; inhibits cardiac sodium channels, prolongs action potential duration, increases effective refractory period, and reduces myocardial excitability and conduction velocity.
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.
100-200 mg orally every 6 hours; immediate-release: 100-200 mg every 6 hours; extended-release: 200-300 mg every 12 hours.
10 mg orally once daily, may increase to 20 mg after 2 weeks if needed.
None Documented
None Documented
Terminal elimination half-life: 6-8 hours (normal renal function); prolonged to 15-25 hours in renal impairment (creatinine clearance <40 mL/min), requiring dose adjustment.
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 excretion of unchanged drug accounts for 40-60% of elimination; hepatic metabolism (N-dealkylation) accounts for 20-30%; approximately 10-15% excreted in feces via biliary elimination.
Renal: 60% unchanged; Biliary/fecal: 30% as metabolites; 10% other.
Category D/X
Category C
Antiarrhythmic (Class Ia)
Antiarrhythmic (Class Ia)