Telmisartan pharmacokinetics in Japanese renal transplant recipients

BackgroundTelmisartan is taken up into human hepatocytes by organic anion-transporting polypeptide (OATP/gene SLCO) and is glucuronized by uridine diphosphate-glucuronosyltransferases (UGTs) into the acylglucuronide, and it is then excreted by transporters such as multidrug resistance 1 (MDR1/gene ABCB1), multidrug resistance protein 2 (MRP2/gene ABCC2), or breast cancer resistance protein (BCRP/gene ABCG2). We elucidated the association of UGTs (1A1, 1A6, 1A7, 1A9 and 2B7), SLCOs (1B1, 1B3 and 2B1), ABCB1, ABCC2 and ABCG2 polymorphisms with steady-state telmisartan pharmacokinetics in 12 Japanese renal transplant recipients.MethodsRecipients were given 40 mg of telmisartan for at least 6 months. Blood was sampled 1 y after transplantation. Plasma concentrations of telmisartan were measured by HPLC.ResultsIn subjects with the ABCC2 − 24C/T genotype, the maximum plasma concentration of telmisartan was significantly greater than that in C/C genotype (96.8 vs. 57.4 ng/ml, respectively, P = 0.0094). In ABCC2 − 24C/C, the second peak plasma concentration of telmisartan was observed 13 h after oral administration, but not ABCC2 − 24C/T genotype group. There was no significant difference in the telmisartan pharmacokinetics between genotype groups of other transporters such as SLCO1B3, ABCB1 and ABCG2 or UGTs.ConclusionsABCC2 genetic polymorphisms appear to strongly influence inter-individual variation of telmisartan pharmacokinetics. MRP2 may be predominantly involved in the telmisartan pharmacokinetics in humans.