The effect of SLCO1B1 polymorphism on the pharmacokinetics of atorvastatin and 2-hydroxyatorvastatin in healthy Chinese people.

The pharmacokinetics of statins show substantial inter-subject variability. Increasing systemic exposure of statins may lead to adverse drug reactions such as myopathy. The variation in statin pharmacokinetics is partly explained by genetic factors. OATP1B1, coded by SLCO1B1 transports a large number of therapeutic drugs, such as atorvastatin. Here we investigated the effect of SLCO1B1 polymorphism on the pharmacokinetics of atorvastatin and its metabolites. Two pharmacokinetic studies were conducted in Chinese Han volunteers and 132 volunteers were enrolled in our study as 72 in trial 1 and 60 in trial 2. A LC-MS/MS method was developed for the identification and quantification of atorvastatin acid and its metabolites. SLCOIB1 c.521T>C (rs4149056) was identified by the MALDI-TOF MS and Sequenom MassARRAY system. The distribution frequencies of SLCO1B1 c.521T>C were in agreement with Hardy-Weinberg equilibrium both in trial 1 and trial 2. In subjects with 521C allele the mean C-max, AUC(0.24h) and AUC(0-infinity) of atorvastatin acid and 2-hydroxyatorvastatin acid were significantly higher than subjects with 521TT genotype, while the mean CL was lower. In conclusion, our results suggested that SLCO1B1 c.521T>C had an effect on the pharmacokinetics of atorvastatin and 2-hydroxyatorvastatin in Chinese Han population. Subjects with 521C allele have an increased risk of toxic effects caused by atorvastatin.