Human Efflux Model
P-glycoprotein (P-gp) is an active transporter that protects the body from some harmful substances (including some drugs) by transporting the substance out of the body or out of sensitive organs. Examples:
- It transports drugs back out of the gut wall into the gut lumen, thus reducing absorption!
- It helps keep some drugs out of the brain.
- It transports drugs out of the kidney into the urine. Some drugs inhibit P-glycoprotein, allowing more of the first drug to be absorbed and less to be excreted, and allowing more of the drug to reach organs such as the brain.