Where do inactivated drug molecules go before excretion?

Where do inactivated drug molecules go before excretion?

• A. The duodenum in the form of bile
• B. The kidneys as urine
• C. The liver as bilirubin
• D. The lungs via exhalation

Answer: (A)

When drugs are inactivated, the liver often conjugates them and sends them into bile. Bile travels from the liver into the duodenum, so these drug metabolites reach the duodenum before excretion. This biliary excretion is a common route for many inactivated molecules, especially larger conjugates, and they may be eliminated in feces or reabsorbed in enterohepatic circulation. In contrast, many drugs are cleared by the kidneys into urine, and inhalation exhalation handles mainly volatile compounds.

When drugs are inactivated, the liver often conjugates them and sends them into bile. Bile travels from the liver into the duodenum, so these drug metabolites reach the duodenum before excretion. This biliary excretion is a common route for many inactivated molecules, especially larger conjugates, and they may be eliminated in feces or reabsorbed in enterohepatic circulation. In contrast, many drugs are cleared by the kidneys into urine, and inhalation exhalation handles mainly volatile compounds.