How is biliary excretion of drugs?

Transporters similar to those in kidney are present in liver hepatocytes and excrete drugs into bile. P-gp transporters (amphipathic molecules) and MRP2 (conjugated metabolites). The drugs are present in bile and go to GI during digestive process Then these drugs may be reabsorbed back (this is the enterohepatic circulation) after hydrolysis by intestinal microflora.