NCIt definition : A dihydropyridine calcium channel blocking agent. Nifedipine inhibits the transmembrane
influx of extracellular calcium ions into myocardial and vascular smooth muscle cells,
causing dilatation of the main coronary and systemic arteries and decreasing myocardial
contractility. This agent also inhibits the drug efflux pump P-glycoprotein which
is overexpressed in some multi-drug resistant tumors and may improve the efficacy
of some antineoplastic agents. (NCI04);