nisoldipine , [ isobutyl methyl 1,4-dihydro-2,6-dimethyl-4- ( 2-nitrophenyl ) -3,5-pyridine carboxylate ] , a calcium antagonist more potent than nifedipine [ 2,6-dimethyl-3,5-dicarbomethoxy-4- ( 2-nitrophenyl ) -1,4-dihydropyridine ] in relaxing vascular smooth muscle , has an affinity three-fold higher than that of nifedipine in competing for the binding sites .
C0028116
nisoldipine
C0012315
dihydropyridine