Drug-metabolizing enzymes (DMEs) and membrane transporters play important roles in the absorption, distribution, metabolism, and excretion processes that determine the pharmacokinetics of drugs. Inflammation has been shown to regulate the expression and function of these drug-processing proteins. Given that inflammation is a common feature of many diseases, in this review, the general mechanisms for inflammation-mediated regulation of DMEs and transporters are described. Also, evidences regarding the aberrant expression of these drug-processing proteins in several inflammatory diseases and age-related disorders are provided. Display omitted •The roles of drug-metabolizing enzymes and transporters (the drug-processing proteins) in pharmacokinetics are introduced.•General mechanisms for the inflammation-mediated regulation of drug-processing proteins are described.•Examples for the regulation of drug-processing proteins in inflammation-related diseases are summarized.