Tariquidar

Tariquidar is a highly selective, potent non-competitive inhibitor of P-glycoprotein. P-glycoprotein actively transports structurally unrelated compounds out of cells, conferring the multidrug resistance phenotype in cancer. P-gp is also expressed in normal tissues like blood brain barrier, gastrointestinal track, liver, spleen and kidney. Tariquidar profoundly inhibited P-glycoprotein in lymphocytes by 93.7% (95% confidence interval, 92.0-95.3%). Tariquidar (XR9576) inhibits the ATPase activity of P-glycoprotein, suggesting that the modulating effect is derived from both inhibition of substrate binding and inhibition of ATP hydrolysis or each of them.