Cellular Uptake of Levocetirizine by Organic Anion Transporter 4

J Pharm Sci. 2017 Sep;106(9):2895-2898. doi: 10.1016/j.xphs.2017.03.026. Epub 2017 Apr 4.


The pharmacokinetics of cetirizine, a nonsedating antihistamine, is profoundly affected by transporter-mediated membrane transport in the kidney. In this study, we aimed to investigate the transport mechanism of levocetirizine, the pharmacologically active enantiomer of cetirizine, via human organic anion transporter 4 (OAT4) expressed in the apical membrane of renal proximal tubules and the basal plasma membrane of placental syncytiotrophoblasts. In cells expressing human OAT4 under the control of tetracycline, levocetirizine uptake was increased by tetracycline treatment. On the other hand, OAT4 expression did not facilitate efflux of preloaded levocetirizine from the cells, either in the presence or absence of extracellular Cl-. The OAT4-mediated levocetirizine uptake was concentration-dependent with a Km of 38 μM. The uptake rate of levocetirizine via OAT4 was approximately twice that of racemic cetirizine, indicating stereoselective uptake of levocetirizine. On the other hand, OAT4-mediated [3H]dehydroepiandrosterone sulfate uptake was inhibited by dextrocetirizine and levocetirizine. Overall, our findings indicate that OAT4 mediates levocetirizine uptake but is unlikely to mediate the efflux.

Keywords: drug transport; membrane transport; organic anion transporters (OAT); pharmacokinetics; placenta; renal transport.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Cell Line
  • Cetirizine / metabolism*
  • Histamine H1 Antagonists, Non-Sedating / metabolism*
  • Humans
  • Kidney / metabolism
  • Kinetics
  • Organic Anion Transporters, Sodium-Independent / metabolism*
  • Trophoblasts / metabolism


  • Histamine H1 Antagonists, Non-Sedating
  • Organic Anion Transporters, Sodium-Independent
  • SLC22A9 protein, human
  • levocetirizine
  • Cetirizine