Comparative Pharmacology
Head-to-head clinical analysis: RYTHMOL versus RYTHMOL SR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: RYTHMOL versus RYTHMOL SR.
RYTHMOL vs RYTHMOL SR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Class Ic antiarrhythmic agent; inhibits sodium channels with slow recovery kinetics, slowing conduction velocity; prolongs PR and QRS intervals.
Class Ic antiarrhythmic agent; sodium channel blocker with slow dissociation kinetics, prolonging atrial and ventricular refractoriness via use-dependent blockade of fast inward sodium channels.
Propafenone 150-300 mg orally every 8 hours; maximum 900 mg/day.
325 mg orally every 12 hours; maximum dose 425 mg every 12 hours.
None Documented
None Documented
Terminal elimination half-life is 10 to 32 hours (mean 20 hours). Clinically, steady-state is achieved in 4-5 days. Half-life increases in hepatic impairment.
Terminal elimination half-life is 10-17 hours (mean ~13 hours) in adults with normal renal function; prolonged in renal impairment or hepatic dysfunction.
Primarily hepatic metabolism; less than 1% excreted unchanged in urine. Approximately 48% of metabolites excreted in urine and 36% in feces.
Renal (approximately 48% as unchanged drug and metabolites), fecal (approximately 35%), biliary (minor).
Category C
Category C
Class Ic Antiarrhythmic
Class Ic Antiarrhythmic