RESUMEN
Considering that the genotypes of CYP2C19 and MDRI C3435T are two major factors attributed to the inter-individual pharmacokinetic variability of lansoprazole (LSZ), the aim of the study was to simultaneously elucidate the effects of CYP2C19 and MDRI C3435T polymorphisms on the pharmacokinetics difference of LSZ and its metabolites 5'-hydroxy lansoprazole (HLSZ) and lansoprazole sulphone (LSZS) following oral administration of LSZ tablets in healthy Chinese subjects. Plasma concentration of LSZ, HLSZ and LSZS were quantified by a sensitive and specific LC-MS/MS method, while the genotypes of CYP2C19 and MDRI C3435T for each subject were identified by a direct sequencing method. Statistical analysis was performed in the pharmacokinetic parameters including Cmax, t1/2, Tmax, MRTo_-, AUCO-2 and AUCo_r among different genotype groups of CYP2C 19 and MDRI C3435T. Compared to the CYP2Cl9 EMs, the CYP2C 19 PM group showed slower elimination and betteroral bioavailability of LSZ, much higher plasma concentrations of LSZS and lower concentrations of HLSZ with statistically significance. Despite a tendency of more favorable absorption and rapid elimination of LSZ in wild genotype, no significant pharmacokinetics difference was observed between the wild genotype of MDR1 C3435T and its mutant types. In conclusion, the pharmacokinetics of MDRI C3435T.