Duration of action and pharmacokinetics of the oral antidiabetic drug gliquidone in patients with non-insulin-dependent (type 2) diabetes mellitus.

ABSTRACT

The duration of action and the pharmacokinetics of gliquidone (1-cyclohexyl-3-[[4-[2-(3,4-dihydro-7-methoxy-4,4-dimethyl-1, 3-dioxo-2(1H)-isochinolyl)ethyl]phenyl]-sulfonyl]-urea, AR-DF 26 SE, CAS 33342-05-1, Glurenorm, Beglynor) were investigated in 32 patients with non-insulin-dependent (type 2) diabetes mellitus over 16 h. In a single-blinded cross-over design vs. placebo, one 30 mg tablet gliquidone was administered 15 min before breakfast. Concomitant to the measurement of glucose and insulin, the gliquidone plasma levels of 20 subjects were determined by a new specific liquid chromatographic (HPLC) assay method with fluorescence detection, and the pharmacokinetic parameters calculated. Following the gliquidone administration, the mean plasma glucose profiles of the responders were up to 15% lower than with placebo (p < 0.005) between 8 a.m. and 6 p.m., representing a duration of the blood sugar-lowering effect of 8 to 10 h. Insulin values were raised, with peaks over 40% higher, during or shortly after meals. Subsequently, the insulin levels returned to approximately the same levels obtained with placebo during the postprandial phase. Plasma concentrations of gliquidone showed pronounced interindividual variability. The mean maximum concentration in plasma Cmax was 0.65 microgram/ml, (range 0.12-2.14 micrograms/ml, coefficient of variation (CV) 82%). The median time to reach maximum plasma concentrations tmax was 2.25 h (range 1.25-4.75 h). The areas under the plasma concentration-time curve from zero time to infinity (AUC0-infinity) and the mean terminal elimination half-lives (t1/2 beta) were computed from those patients (N = 8) who exhibited at least five plasma levels above the limit of quantitation in the terminal log-linear phase using a two-compartment model the mean AUC0-infinity was 5.1 micrograms.h/ml (range 1.5-10.1 micrograms.h/ml, CV 56%). The dominant half-life t1/2 alpha derived from therapeutically relevant plasma levels of gliquidone (> 80 ng/ml) was approximately 1.2 h (range 0.4-3.0 h. CV 71%) and the mean terminal half-life t1/2 beta was approximately 8 h (range 5.7-9.4 h, CV 17%). From the pharmacodynamic behavior as well as from the pharmacokinetic parameters it can be deduced that gliquidone belongs to the class of short-acting sulfonylureas used in antidiabetic therapy.