What is MDR?
Multidrug resistance is the ability of pathologic cells to withstand chemicals that are designed to aid in the eradication of such cells. These pathologic cells include bacterial and neoplastic (tumor) cells. Cancer cells also have the ability to become resistant to multiple different drugs, and share many of the same mechanisms: Increased efflux of drug (as by P-glycoprotein, multidrug resistance-associated protein, lung resistance related protein, and breast cancer resistance protein) Enzymatic deactivation (i.e. glutathione conjugation) Decreased permeability (drugs can’t enter the cell) Altered binding-sites Alternate metabolic pathways (the cancer compensates for the effect of the drug).