P –Glycoprotein (P-gp) – Drug Interactions:

v P-glycoprotein is one of the transporter protein and it helps the drugs and endogenous substances to cross biological membranes, by carrier-mediated processes.

v P-gp Substrates:

Digoxin, Loperamide, Quinidine, Vinblastine, Talinolol.

v P-gp Inducers:

Carbamazepine, Phenytoin, Rifampin, St John’s wort.

v P-gp Inhibitors:

Amiodarone, Azithromycin, Captopril, Cyclosporine, Quinidine, Quinine, Reserpine, Ritonavir, Tacrolimus, Valspodar, Verapamil.

v P-glycoprotein is an efflux pump found in the membranes of certain cells, which can push metabolites and drugs out of the cells and affect drugs’

ü Absorption (in the intestine)

ü Distribution (to the brain, testis, or placenta)

ü Elimination (in the urine and bile) of drugs

v Many drugs which are substrates for CYP3A4 are also substrates for P-glycoprotein.

v There is an overlap between CYP3A4 and P-glycoprotein inhibitors, inducers and substrates.