Single-dose pharmacokinetics and dose proportionality of oral cibenzoline

The pharmacokinetics of cibenzoline were evaluated in four young healthy volunteers who received ascending oral doses of 65, 97.5, 130, 162.5, 195, 227.5, and 260 mg separated by one week. Cibenzoline plasma concentrations exhibited an apparent biexponential decline following oral absorption. Maximum plasma concentrations and area under the plasma concentration-time curve increased in proportion to the dose. The mean elimination half-life among subjects was independent of dose and ranged from 7.3 to 8.7 hours. Oral clearance ranged from 380 to 575 ml/min and was also independent of dose. A single pharmacokinetic equation was used to adequately describe the plasma concentration data over the entire range of doses for each subject, indicating dose-proportional and linear pharmacokinetics.