Drug Transporters

Membrane transporters play a central role in protecting the body from xenobiotics (either by preventing their absorption, limiting their distribution, or promoting their elimination). Transporters can also participate in trafficking and compartmentalization of physiological compounds. In some cases, they may favor drug absorption and/or distribution, or act as pharmacological targets for therapeutic interventions; accordingly, they are of major pharmacological importance. Transporter protein science is an emerging field and the identification and characterization of pharmaceutically and medically relevant drug transporters continue to evolve. The medical and pharmaceutical impact of drug transporters is being increasingly recognized, but is still far from being fully understood. In relation to drug kinetics, two transporter superfamilies are of particular importance: ATP-binding cassette (ABC) transporters and solute carrier (SLC) transporters. Both of these are discussed in this chapter.