Dofequidar fumarate(MS-209 fumarate), an orally active quinoline compound, has been reported to overcome MDR by inhibiting ABCB1/P-gp, ABCC1/MDR-associated protein 1, or both.

Elacridar is an orally selectly potent P-glycoprotein (P-gp/ABCG1) inhibitor.

LY335979 (Zosuquidar) is a potent modulator of P-glycoprotein-mediated multidrug resistance with Ki of 60 nM.

Tariquidar (XR9576) is a potent and selective noncompetitive inhibitor of P-glycoprotein with Kd of 5.1 nM.

Valspodar(PSC833) is a P-glycoprotein (P-gp) inhibitor widely used in preclinical and clinical studies for overcoming multidrug resistance (MDR).

(R)-Verapamil hydrochloride ((R)-(+)-Verapamil hydrochloride) is a P-Glycoprotein inhibitor. (R)-Verapamil hydrochloride blocks MRP1 mediated transport, resulting in chemosensitization of MRP1-overexpressing cells to anticancer drugs.

Roemerine, an aporphine alkaloid, isolated from the leaves of Annona senegalensis, functions by interacting with P-glycoprotein. Roemerine reverses the multidrug-resistance phenotype with cultured cells.

(R)-Verapamil D7 hydrochloride ((R)-(+)-Verapamil D7 hydrochloride) is a deuterium labeled (R)-Verapamil hydrochloride. (R)-Verapamil hydrochloride ((R)-(+)-Verapamil hydrochloride) is a P-Glycoprotein inhibitor. (R)-Verapamil hydrochloride blocks MRP1 mediated transport, resulting in chemosensitization of MRP1-overexpressing cells to anticancer drugs.

Phellamurin is a plant flavonone glycoside from the leaves of Phellodendron amurense and inhibits intestinal P-glycoprotein. Phellamurin also inhibits egg laying by Papilio protenor. Phellamurin induces cells apoptosis and has anti-tumor activity.

Boeravinone B, a dual inhibitor of NorA bacterial efflux pump of Staphylococcus aureus and human P-Glycoprotein, reduces the biofilm formation and intracellular invasion of bacteria. Boeravinone B act as anti-aging and anti-apoptosis phyto-molecules during oxidative stress.

WS-898 is a highly effective ABCB1 inhibitor capable of reversing paclitaxel (PTX) resistance in drug-resistant SW620/Ad300, KB-C2, and HEK293/ABCB1 cells (IC50 = 5.0, 3.67, and 3.68 nM, respectively).

YS-370 (compound 44) is a potent, high selective, and orally active inhibitor of P-glycoprotein (P-gp). YS-370 stimulates the P-gp ATPase activity and has moderate inhibition against CYP3A4. YS-370 effectively reverses multidrug resistance (MDR) to paclitaxel and colchicine in SW620/AD300 and HEK293T-ABCB1 cells. YS-370 in combination with paclitaxel achieves much stronger antitumor activity.

P-gp inhibitor 2 is a potent P-gp inhibitor. P-gp inhibitor 2 shows reverse Doxorubicin resistance (IC50=0.22 µM) in P-gp overexpressing human colorectal carcinoma cells (SW600 Ad300).

P-gp inhibitor 3 is an effective P-glycoprotein (P-gp) inhibitor. P-gp inhibitor 3 inhibits the efflux function of P-gp by activating P-gp ATPase. P-gp inhibitor 3 has relatively stronger multidrug resistance (MDR) reversal ability and enhances the anti-tumor activity of Paclitaxel.

Encequidar (HM30181) is a potent selective inhibitor of MDR1 (ABCB1, P-gp) with IC50 of 0.63 nM.Encequidar (HM30181) effectively blocked transepithelial transport of paclitaxel in MDCK monolayers.Encequidar (HM30181) does not inhibit MRP1 (ABCC1), MRP2 (ABCC2), and MRP3 (ABCC3), and partially inhibited BCRP (ABCG2) only at very high concentrations.Oral co-administration of paclitaxel and HM30181 showed a tumor-inhibitory strength equal or superior to that of intravenous paclitaxel in the xenograft model in nude mice.

PGP-4008 is a specific P-glycoprotein (Pgp) inhibitor. PGP-4008 inhibits tumor growth in a murine syngeneic Pgp-mediated multiple drug resistance (MDR) solid tumor model when given in combination with Doxorubicin.

Reversin 121 is a P-glycoprotein inhibitor. Reversin 121 increases the ATPase activity of MDR1. Reversin 121 reverses P-glycoprotein-mediated multidrug resistance. Reversin 121 can be used in the research of cancers.

FM04 is a potent P-glycoprotein (P-gp) inhibitor (EC50=83 nM). FM04 inhibits P-gp in 2 mechanism: (1)FM04 binds to Q1193, followed by interacting with the functionally critical residues H1195 and T1226; or (2)FM04 binds to I1115 (a functionally critical residue itself), disrupting the R262-Q1081-Q1118 interaction pocket and uncoupling ICL2-NBD2 interaction and thereby inhibiting P-gp.