Biliary drug clearance (CLb)

Biliary drug clearance is a physiological process and pharmacokinetic parameter that represents the elimination of drugs and their metabolites from the body via secretion from hepatocytes into the bile (StatPearls). This process is primarily mediated by various transport proteins on the canalicular membrane of the liver, including P-glycoprotein (ABCB1), Multidrug Resistance-associated Protein 2 (MRP2), and Breast Cancer Resistance Protein (BCRP), often following uptake from the blood by sinusoidal transporters like OATP1B1 and OATP1B3 (PubMed). This pathway is particularly critical for drugs with high molecular weight or those that are actively conjugated, such as glucuronides or glutathione conjugates (ResearchGate). Interference with this process, through genetic variation or inhibition by co-administered drugs, can significantly alter pharmacokinetics and lead to adverse effects like drug-induced liver injury (DILI) or cholestasis (PubMed Central). It is a fundamental consideration in drug development for assessing potential drug-drug interactions (DDI) and ensuring patient safety across diverse populations.

Other names

Biliary excretionHepatobiliary clearanceBiliary drug excretionBiliary elimination

Drugs are cleared through the biliary system via active transport mediated by sinusoidal uptake transporters (e.g., OATPs) and canalicular efflux transporters (e.g., P-gp, MRP2, BCRP, BSEP) which move compounds from hepatocytes into the bile canaliculi.