Inhibitors of p-glycoprotein--lead identification and optimisation

The membrane bound drug efflux pump P-glycoprotein (P-gp) transports a wide variety of functionally and structurally diverse cytotoxic drugs out of tumour cells. Overexpression of P-glycoprotein is one of the predominant mechanisms responsible for development of multiple drug resistance in tumour therapy. Thus, inhibition of P-gp represents a promising approach for treatment of multidrug resistant tumours. This review highlights concepts for identification and optimization of new inhibitors of P-glycoprotein.