Pharmacokinetics Ibutilide

1 pharmacokinetics

1.1 absorption
1.2 distribution
1.3 metabolism
1.4 excretion

pharmacokinetics
absorption

ibutilide intravenously administered. has high first-pass metabolism, results in poor bioavailability when taken orally. individual pharmacokinetic properties highly viable during clinical trial.

distribution

ibutilide has relatively large volume of distribution among individual subjects, 11l/kg. approximately 40% of drug bound plasma albumin of healthy volunteers in trial. approximately close patients atrial fibrillation , flutter.

metabolism

ibutilide has high systemic plasma clearance closes hepatic blood flow (29ml/min/kg). metabolic pathway via liver’s cytochrome p450 system isoenzymes other cyp3a4 , cyp2d6 heptyl side chain of ibutilide oxidized. 8 metabolites detected in urine, however, 1 active metabolite shares similar electrophysiologic property of class iii antiarrhythmic agents. plasma concentration of metabolite less 10% of ibutilide.

excretion

after administration of ibutilide, excreted renal pathway half-life of approximately 6 hours. approximately 82% of 0.01 mg/kg dose excreted in urine during trial. among those, around 7% excreted unchanged drug. reminder of drug excreted in feces (about 19%).