Enterohepatic recycling

ALAN TALEVI; CAROLINA L. BELLERA

The ADME Encyclopedia. A Comprehensive Guide on Biopharmacy and Pharmacokinetics

Springer Nature

Lugar: Basignstoke; Año: 2022; p. 464 - 471

Broadly speaking, enterohepatic recycling (or enterohepatic circulation) involves the circulation of metabolized and non-metabolized compounds (including physiologic compounds and xenobiotics) between the intestine and the liver [1, 2]. Some xenobiotics and some endogenous substances (e.g. bile acids) after their elimination into the intestine by the liver, are reabsorbed, entering an enterohepatic cycle [1]. Enterohepatic circulation can be regarded as the phenomenon of the transport of chemical compounds from the liver to the bile, which eventually drains into intestine and is followed by reabsorption and then back into the liver. The intestinal microbiota plays a central role in the enterohepatic recycling phenomenon [3]. Enterohepatic circulation increases the elimination half-life of many drugs (thus prolonging their action) and causes multiple peaks in the plasma drug concentration-time profile, which are frequently elusive in terms of pharmacokinetic modeling. In some cases, enterohepatic recycling may have a substantial toxicological impact [2], as it can detoxify already detoxified xenobiotic molecules, and some organs, i.e. the intestine and the liver, which may be reiteratively exposed to the drug.