Nathan J Cherrington
Numerous drug-induced and environmental exposure-related toxicities are the result of inter-individual variation in the ADME processes of absorption, distribution, metabolism and elimination that control the fate of these compounds from the body. Alterations in these processes provide the mechanistic basis for individual variability in response to drugs and environmental exposures. A common perception is that variability in response is due to genetic polymorphisms within the drug metabolizing enzyme and transporter genes. While there are numerous examples of these differences that play a major role in the susceptibility of genetic subpopulations for specific toxicities, the potential for transient phenotypic conversion due to temporary environmental changes, such as inflammation and disease, are often overlooked.Due to the ensuing liver damage caused by the progressive stages of NAFLD, gene expression patterns can change dramatically resulting in a phenoconversion resembling genetic polymorphisms. Because the liver plays such a key role in the metabolism and disposition of xenobiotics, this temporary phenoconversion could lead to the inability of patients to properly metabolize and excrete drugs and environmental toxicants, increasing the risk of some adverse drug reactions and environmental toxicities.