Extrahepatic Drug Transporters in Liver Failure: Focus on Kidney and Gastrointestinal Tract

Emerging information suggests that liver pathological states may affect the expression and function of membrane transporters in the gastrointestinal tract and the kidney. Altered status of the transporters could affect drug as well as endogenous compounds handling with subsequent clinical consequences. It seems that changes in intestinal and kidney transporter functions provide the compensatory activity of eliminating endogenous compounds (e.g., bile acids) generated and accumulated due to liver dysfunction. A literature search was conducted on the Ovid and PubMed databases to select relevant in vitro, animal and human studies that have reported expression, protein abundance and function of the gastrointestinal and kidney operating ABC (ATP-binding cassette) transporters and SLC (solute carriers) carriers. The accumulated data suggest that liver failure-associated transporter alterations in the gastrointestinal tract and kidney may affect drug pharmacokinetics. The altered status of drug transporters in those organs in liver dysfunction conditions may provide compensatory activity in handling endogenous compounds, affecting local drug actions as well as drug pharmacokinetics.