The Role of Dopamine Receptors in the Treatment of Congestive Heart Failure

Dopamine (DA) has been used for more than 25 years for treatment of congestive heart failure (CHF). Low infusion rates of DA (approximately 0.2-2 micrograms/kg/min) activate DA1 and DA2 dopamine receptors. Action on DA1 receptors results in vasodilation, primarily in the renal, mesenteric, and coronary vascular beds, and induces natriuresis. Action on DA2 receptors causes inhibition of norepinephrine release from sympathetic nerves. At medium infusion rates (approximately 2-5 micrograms/kg/min), beta 1-adrenoceptors are recruited and cardiac contractility increases. This infusion rate is usually used for the treatment of CHF. DA agonists with different receptor action than DA produce beneficial hemodynamic effects in patients with CHF: propylbutyl-DA (DA1 and DA2 receptors), bromocriptine (DA2 receptors), fenoldopam (DA1 receptors), and dopexamine (DA1 and DA2 receptors, and beta 2-adrenoceptors). Oral administration of three prodrugs (levodopa, ibopamine, and TA-8704) improve hemodynamics in patients with chronic CHF. Additional studies are required to determine whether drugs acting on DA receptors will have unique value in the long-term treatment of CHF.