Abstract: Dihydropyridine derivatives and salts thereof represented by the general formula, ##STR1## which possess excellent calcium antagonist effect, hypotensive effect, platelets aggregation inhibitory effect, phosphodiesterase inhibitory effect, calmodulin inhibitory effect and peroxidized lipid lowering effect, and thus dihydropyridine derivatives and salts thereof are useful as a coronary blood flow improving agent such as coronary vasodilator, hypotensive agent, prophylaxis and treating agents for thrombosis, phophodiesterase inhibitory agent, peroxidized lipid metabolism lowering agent, anti-inflammatory agent and others.

Abstract: Novel carbostyril derivatives and salts thereof having useful pharmacological activities such as myocardial contraction increasing activity (positive inotropic activity), coronary blood flow increasing activity, hypotensive activity, activity for inhibiting vasoconstriction induced by norepinephrine, and anti-inflammatory effect in one hand, while they do not possess activity for increasing heart beat at all substantially as well as show quite low toxicity and low side-effects in central nervous system activities.