C3435T Mutation in Exon 26 of the Human MDR1 Gene and Cyclosporine Pharmacokinetics in Healthy Subjects.

摘要

SUMMARY: To determine the relationship between C3435T mutation in exon 26 of the human multidrug resistant 1 (MDR1) gene and cyclosporine pharmacokinetic parameters among healthy volunteers, the oral cyclosporine pharmacokinetic study was performed for 14 healthy subjects. Blood cyclosporine concentrations were measured by HPLC. Concentration-time data were analyzed by a noncompartmental method using WinNonLin, and the blood samples were genotyped for the C3435T polymorphism of MDR1 gene using the PCR and a restriction digest. Each cyclosporine pharmacokinetic parameter was compared using the Mann-Whitney U test according to his or her P-gp genotype. There were seven (7) homozygous C/C, six (6) C/T, and one (1) homozygous T/T genotypes in these 14 healthy volunteers. According to their genotypes, mean tmax 1.6 +/- 0.3 hours, mean Cmax 1337 +/- 329 ng/mL, mean Cl/F 66.5 +/- 18.3 L/h, and mean AUC 5642 +/- 1577 ng.h/mL in C/C group and mean tmax 2.0 +/- 0.6 hours, mean Cmax 1540 +/- 721 ng/mL, mean Cl/F 55.2 +/- 18.9 L/h, and mean AUC 6902 +/- 1405 ng.h/mL in C/T+T/T group. Although Cmax and AUC in C/T and T/T group were 15% and 22% larger than those in C/C group, none of these parameter comparisons was statistically significant. There were no statistical differences in cyclosporine pharmacokinetics among different MDR1 genotypes in these 14 healthy subjects.