It is widely believed that P-glycoprotein, together with other ATP efflux drug transporters, plays a crucial role in the host detoxication and protection against xenobiotic substances. On the other hand, the presence of these transporters in normal tissues may prevent pharmacotherapeutic agents from reaching their site of action, thus limiting their therapeutic potential.
This review focuses on P-glycoprotein, its expression, localization, and function in nontumor tissues and the pharmacological consequences hereof. Special attention is paid to its role in pharmacokinetics of the small intestine, brain, kidney, liver and placenta.