Multidrug resistance and anticonvulsants: new studies with some enaminones.

The multidrug resistance (MDR), often conferred by the active extrusion of drugs from the cell, is a phenomenon often seen in cancer cells that may become resistant to a wide spectrum of drugs with varying chemical structures or cellular targets. This event has recently been reported for anticonvulsants. Studies in our laboratories on this occurrence with some enaminones have shown that the enaminones display high efflux ratios and are recognized by P-glycoprotein (P-gp) and/or the multidrug resistance protein (MRP), which have been reported as the main efflux transporters responsible for the development of MDR. Recent studies have uncovered interesting structural analogues that can modulate the functional activity of P-gp, suggesting a possible increase in the bioavailabillity of P-gp substrate drugs when administered concurrently. Copyright 2004 Bentham Science Publishers Ltd.