Genetic Polymorphisms of Metabolic Enzymes and the Pharmacokinetics of Indapamide in Taiwanese Subjects
Journal Title: The AAPS Journal - Year 2014, Vol 16, Issue 2
Abstract
To understand the genetic makeup and impact on pharmacokinetics (PK) in the Taiwanese population, we analyzed the pharmacogenetic (PG) profile and demonstrated its effects on enzyme metabolism using indapamide as an example. A multiplex mass spectrometry method was used to examine the single nucleotide polymorphism (SNP) profile of eight major phases I and II metabolic enzymes in 1,038 Taiwanese subjects. A PG/PK study was conducted in 24 healthy subjects to investigate the possible effects of 28 SNPs on drug biotransformation. Among the genetic profile analyzed, eight SNPs from CYP2A6, CYP2C19, CYP2D6, CYP2E1, CYP3A5, and UGT2B7 showed higher variant frequencies than those previously reported in Caucasians or Africans. For instance, we observed 14.7% frequency of the SNP rs5031016 (I471T) from CYP2A6 in Taiwanese, whereas 0% variation was reported in Caucasians and Africans. The PG/PK study of indapamide demonstrated that the polymorphic SNPs CYP2C9 rs4918758 and CYP2C19 rs4244285 appeared to confer lowered enzyme activity, as indicated by increased Cmax (25% ∼ 64%), increased area under the plasma level-time curves (30∼76%), increased area under the time infinity (43% ∼ 80%), and lower apparent clearance values than PK for wild-type indapamide. Our results reinforce the biochemical support of CYP2C19 in indapamide metabolism and identify a possible new participating enzyme CYP2C9. The PG/PK approach contributed toward understanding the genetic makeup of different ethnic groups and associations of enzymes in drug metabolism. It could be used to identify two genetic markers that enable to differentiate subjects with varied PK outcomes of indapamide.
Authors and Affiliations
Teng-Hsu Wang, Cheng-Huei Hsiong, Hsin-Tien Ho, Tung-Yuan Shih, San-Jan Yen, Hui-Hung Wang, Jer-Yuarn Wu, Benjamin Pei-Chung Kuo, Yuan-Tsong Chen, Shung-Tai Ho, Oliver Yoa-Pu Hu
Population Pharmacokinetics of Cyclosporine in Transplant Recipients
A number of classical pharmacokinetic studies have been conducted in transplant patients. However, they suffer from some limitations, for example, (1) the study design was limited to intense blood sampling in small group...
A Bayesian Approach for Quantifying Trace Amounts of Antibody Aggregates by Sedimentation Velocity Analytical Ultracentrifugation
Sedimentation velocity analytical ultracentrifugation (SV-AUC) has become an important tool for the characterization of the purity of protein therapeutics. The work presented here addresses a need for methods orthogonal...
GATG Dendrimers and PEGylated Block Copolymers: from Synthesis to Bioapplications
Dendrimers are synthetic macromolecules composed of repetitive layers of branching units that emerge from a central core. They are characterized by a tunable size and precise number of peripheral groups which determine t...
Influence of drug release properties of conventional solid dosage forms on the systemic exposure of highly soluble drugs
This study was designed to theoretically investigate the influence of drug release properties, characterized by the disintegration of a solid dosage form and dissolution of drug particles, on the systemic exposure of hig...
Development and characterization of a recombinant madin-darby canine kidney cell line that expresses rat multidrug resistance-associated protein 1 (rMRP1)
Multidrug resistance-associated protein 1 (MRP1) is one of the major proteins shown to mediate efflux transport of a broad range of antitumor drugs, glucuronide conjugates, and glutathione, in addition to endogenous subs...