The optically active compound (R)-2-amino-1,4-dihydro-6-methyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid 3-(1-diphenylmethylazetidin-3-yl) ester 5-isopropyl ester or a pharmacologically acceptable salt thereof, and a method using the compound or its salt to treat circulatory diseases.
The optically active dihydropyridine derivative is (R)-2-amino-1,4-dihydro-6-methyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid 3-(1-diphenylmethylazetidin-3-yl) ester 5-isopropyl ester or a pharmacologically acceptable salt thereof.