The biliary system of the liver, crucial for bile secretion and drug excretion, comprises intrahepatic bile ducts that merge to form the common hepatic duct. This duct, carrying hepatic bile, combines with the cystic duct, draining the gallbladder and forming the common bile duct, which empties into the duodenum. Bile, produced by hepatic cells lining the bile canaliculi, is composed primarily of water, bile salts, pigments, electrolytes, and lesser amounts of cholesterol and fatty acids. Bile...

The liver plays a pivotal role in eliminating drugs and their metabolites, primarily through a process known as biliary excretion. This process involves the hepatocytes, the primary cells in the liver that generate bile. A range of transporters actively expels polar drugs or hydrophilic drug metabolites into the bile, which transports the drugs and metabolites into the small intestine. From here, they are eventually expelled from the body through feces. In some instances, the original drug or a...

In clinical practice, the direct measurement of hepatic blood flow to evaluate liver function presents significant challenges due to the intricate and specialized nature of the necessary techniques. Consequently, healthcare professionals often rely on empirical estimates derived from thorough patient examinations and liver function tests to gauge liver health. Among the tools at their disposal, the Child–Pugh and MELD scoring systems stand out for their ability to categorize and assess the...

Enterohepatic cycling involves the active secretion of drugs and their metabolites into the bile via transporters in the canalicular membrane of hepatocytes. This secretion is an integral part of the digestive process, releasing these substances into the gastrointestinal (GI) tract.
Post-release drugs and metabolites can be reabsorbed into the body from the intestine. For conjugated metabolites like glucuronides, reabsorption requires enzymatic hydrolysis by intestinal microflora. This...

Poison can be effectively removed from the gastrointestinal (GI) tract through various decontamination procedures.
Antidotes serve a crucial role in counteracting the effects of poison by inhibiting enzymes responsible for producing harmful drug metabolites. In some cases, these toxic metabolites can be neutralized by endogenous cosubstrates, which are maintained at specific concentrations to prevent interaction with cellular macromolecules and subsequent cell death.
Renal excretion is the...

In the liver and bile canaliculi, influx and efflux transporters modification can influence intrinsic clearance. Transporters play a significant role in moving drugs within liver cells. Elaborate models, such as the Biopharmaceutical Classification System (BCS), are essential to relate transporters to drug disposition. This system categorizes drugs into four classes based on solubility and permeability, providing insights into elimination routes and the effects of transporters following oral...