Which organ is responsible for excretion of some drugs via expired air?

Which organ is responsible for excretion of some drugs via expired air?

• A. Brain
• B. Kidneys
• C. Liver
• D. Lungs

Answer: (D)

Volatile inhaled anesthetics are eliminated through the lungs. They move from the blood into the alveolar air and are exhaled, so the rate at which they disappear from the body depends on how quickly this alveolar air is refreshed. The speed of elimination hinges on the drug’s blood-gas partition coefficient: agents with low solubility in blood exit rapidly, while more soluble ones linger longer. While the liver and kidneys handle most other drug metabolism and excretion, the excretion via expired air is the primary route for these volatile anesthetics.

Volatile inhaled anesthetics are eliminated through the lungs. They move from the blood into the alveolar air and are exhaled, so the rate at which they disappear from the body depends on how quickly this alveolar air is refreshed. The speed of elimination hinges on the drug’s blood-gas partition coefficient: agents with low solubility in blood exit rapidly, while more soluble ones linger longer. While the liver and kidneys handle most other drug metabolism and excretion, the excretion via expired air is the primary route for these volatile anesthetics.