Comparative Pharmacology
Head-to-head clinical analysis: BRETYLIUM TOSYLATE versus DOFETILIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BRETYLIUM TOSYLATE versus DOFETILIDE.
BRETYLIUM TOSYLATE vs DOFETILIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Bretylium tosylate is a class III antiarrhythmic agent that prolongs the action potential duration and refractory period by blocking potassium channels. It also initially causes norepinephrine release, leading to transient hypertension and increased contractility, followed by adrenergic neuron blockade, resulting in hypotension and reduced contractility.
Selectively blocks the rapid component of the delayed rectifier potassium current (Ikr) in cardiac myocytes, prolonging repolarization and the effective refractory period.
For ventricular tachycardia/fibrillation: 5-10 mg/kg IV bolus over 1-2 minutes, may repeat every 15-30 minutes up to 30 mg/kg total. Maintenance: 5-10 mg/kg IV every 6 hours or 0.5-2 mg/min continuous infusion. Intramuscular: 5-10 mg/kg undiluted, may repeat every 1-2 hours.
250-500 mcg orally twice daily, based on creatinine clearance and QTc response.
None Documented
None Documented
Clinical Note
moderateDofetilide + Levofloxacin
"Dofetilide may increase the QTc-prolonging activities of Levofloxacin."
Clinical Note
moderateDofetilide + Norfloxacin
"Dofetilide may increase the QTc-prolonging activities of Norfloxacin."
Clinical Note
moderateDofetilide + Gemifloxacin
"Dofetilide may increase the QTc-prolonging activities of Gemifloxacin."
Clinical Note
moderateDofetilide + Torasemide
"Dofetilide may increase the QTc-prolonging activities of Torasemide."
5-10 hours; prolonged in renal impairment (up to 30 hours)
Terminal elimination half-life: 10 hours (range 7–13 hours) in patients with normal renal function; prolonged in renal impairment, up to 20 hours in moderate impairment and >30 hours in severe impairment.
Renal: ~80% unchanged; biliary/fecal: <1%
Renal: 80% unchanged; biliary/fecal: 20% as metabolites and unchanged drug.
Category C
Category C
Antiarrhythmic (Class III)
Antiarrhythmic (Class III)