Comparative Pharmacology
Head-to-head clinical analysis: NORPACE CR versus QUINALAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORPACE CR versus QUINALAN.
NORPACE CR vs QUINALAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Class Ia antiarrhythmic agent; decreases myocardial excitability and conduction velocity, and prolongs refractory period by blocking sodium channels.
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.
Disopyramide controlled-release: 200 mg orally every 12 hours; maximum 400 mg/day.
10 mg orally once daily, may increase to 20 mg after 2 weeks if needed.
None Documented
None Documented
Terminal elimination half-life: 6-12 hours (normal renal function); prolonged to 12-20 hours in renal impairment. In coronary artery disease, half-life may be extended due to reduced clearance.
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 (50-57% unchanged), hepatic metabolism (30-40%), fecal (<10%). Dose adjustment required for CrCl <40 mL/min.
Renal: 60% unchanged; Biliary/fecal: 30% as metabolites; 10% other.
Category C
Category C
Antiarrhythmic (Class Ia)
Antiarrhythmic (Class Ia)