Which statement best describes the overall action of P-glycoprotein?

Which statement best describes the overall action of P-glycoprotein?

• A. P-gp increases absorption by transporting drugs into the blood
• B. P-gp reduces absorption and can excrete drugs into bile or urine
• C. P-gp affects only intestinal absorption and not excretion
• D. P-gp is not energy-dependent

Answer: (B)

P-glycoprotein functions as an ATP-dependent efflux transporter, moving drugs out of cells. In the intestinal lining, it pushes drugs back into the lumen, which lowers how much is absorbed. In the liver and kidneys, it helps eliminate drugs by secreting them into bile or urine. So its overall action is to reduce absorption and promote excretion, shaping both how much of a drug gets into the bloodstream and how quickly it is cleared from the body. It is energy-dependent, and it acts beyond the intestine, not just there. That combination makes the statement about reducing absorption and enabling excretion into bile or urine the best description.

P-glycoprotein functions as an ATP-dependent efflux transporter, moving drugs out of cells. In the intestinal lining, it pushes drugs back into the lumen, which lowers how much is absorbed. In the liver and kidneys, it helps eliminate drugs by secreting them into bile or urine. So its overall action is to reduce absorption and promote excretion, shaping both how much of a drug gets into the bloodstream and how quickly it is cleared from the body. It is energy-dependent, and it acts beyond the intestine, not just there. That combination makes the statement about reducing absorption and enabling excretion into bile or urine the best description.