Influence of CYP2C9 and CYP2C19 genetic polymorphisms on pharmacokinetics of gliclazide MR in Chinese subjects

Br J Clin Pharmacol. 2007 Jul;64(1):67-74. doi: 10.1111/j.1365-2125.2007.02846.x. Epub 2007 Feb 12.


Aims: To investigate the influence of CYP2C9 and CYP2C19 genetic polymorphisms on the pharmacokinetics of gliclazide modified release (MR) in healthy Chinese subjects.

Methods: In a single-dose pharmacokinetic study, 24 healthy male subjects with various CYP2C9 and CYP2C19 genotypes received an oral dose of 30 mg gliclazide MR and plasma was sampled for 72 h postdose. In a multiple-dose pharmacokinetic study, 17 other CYP2C9*1 homozygotes with various CYP2C19 genotypes received 30 mg gliclazide MR once daily for 6 days and plasma was sampled after the last dose. The plasma concentrations of gliclazide were measured using a validated LC/MS/MS method. CYP2C9 and CYP2C19 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis.

Results: In the single-dose study, no significant difference in any pharmacokinetic parameters was found in CYP2C9*1/*1, *1/*3 and *1/*13 subjects. In contrast, the AUC(0-infinity) of gliclazide was significantly increased by 3.4-fold [95% confidence interval (CI) 2.5, 4.7; P < 0.01] in CYP2C19 poor metabolizer (PM) subjects compared with CYP2C19*1 homozygotes. The half-life (t(1/2)) was prolonged from 15.1 to 44.5 h (P < 0.01). Similar differences were found in the multiple-dose study. The parameters of gliclazide AUC(ss), AUC(0-infinity) and C(max) were 3.4-fold (95% CI 2.9, 4.0), 4.5-fold (95% CI 3.8, 5.4) and 2.9-fold (95% CI 2.4, 3.4) increased (P < 0.01) in CYP2C19 PM subjects, respectively, compared with CYP2C19*1 homozygotes, and t(1/2) was increased from 13.5 to 24.6 h (P < 0.01).

Conclusions: The pharmacokinetics of gliclazide MR are affected mainly by CYP2C19 genetic polymorphism instead of CYP2C9 genetic polymorphism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aryl Hydrocarbon Hydroxylases / genetics
  • Asians / genetics
  • Blood Glucose / metabolism*
  • Cytochrome P-450 CYP2C19
  • Cytochrome P-450 CYP2C9
  • Dose-Response Relationship, Drug
  • Genotype
  • Gliclazide / blood
  • Gliclazide / pharmacokinetics*
  • Humans
  • Hypoglycemic Agents / blood
  • Hypoglycemic Agents / pharmacokinetics*
  • Male
  • Mixed Function Oxygenases / genetics
  • Polymorphism, Genetic


  • Blood Glucose
  • Hypoglycemic Agents
  • Mixed Function Oxygenases
  • CYP2C9 protein, human
  • Cytochrome P-450 CYP2C9
  • Aryl Hydrocarbon Hydroxylases
  • CYP2C19 protein, human
  • Cytochrome P-450 CYP2C19
  • Gliclazide