And Answers
Critical Thinking Intravenous drug administration bypasses drug absorption and
metabolism, Carrier proteins transport drugs based on their chemical characteristics
P-glycoprotein (P-gp) Active efflux pump for anticancer drugs, Member of ATP-binding
cassette (ABC) transporters
Organ distribution P-gp: Intestine, Liver, Kidney, Placenta, Blood-brain barrier (BBB),
Pancreas, Colon, Testis, BCRP: Intestine, Liver, Kidney, Placenta, BBB, Bronchi, MRP2:
Intestine, Liver, Kidney, Placenta, BBB, Mammary glands
Drug distribution Volume of distribution (Vd), Factors affecting drug distribution, Gut
transport, Liver metabolism, Cardiac output and blood flow, Physicochemical properties of
drugs, Plasma protein binding, Tissue binding and absorption/transport
Small Intestinal transporters Almost equal number of influx and efflux transporters in both
lumen and blood sides of the small intestine
Liver transporters More influx than efflux transporters in the blood side, but more efflux
than influx transporters in the bile side of the liver