Dopamine exerts an inotropic effect on the myocardium resulting in an increased cardiac output.
Dopamine produces less increase in myocardial oxygen consumption than isoproterenol and its use is usally not associated with a tachyarrhythmia. Clinical studies indicate that dopamine at low and intermediate therapeutic doses usually increases systolic and pulse pressure with either no effect or a slight increase in diastolic pressure, and total peripheral resistance is usually unchanged. Blood flow to peripheral vascular beds may decrease while mesenteric flow increases. Dopamine has also been reported to dilate the renal vasculature presumptively by activation of a dopaminergic receptor. This action is accompanied by increases in glomerular filtration rate, renal blood flow, and sodium excretion.