Beta-Adrenergic and Dopaminergic Receptor Agonists

Dopamine [dope' a meen]
Dobutamine [doe bue' ta meen]

  • Dopamine and dobutamine are used for short-term inotropic support of the failing heart.

  • Dobutamine is less arrhythmogenic and produces less tachycardia compared to endogenous catecholamines or isoproterenol.


  • Dobutamine is a racemate that binds to and activates beta-1 and beta-2 adrenoceptor subtypes. The (-) enantiomer stimulates alpha 1 and alpha 2 receptors, but this effect in humans appear negated by binding of the inactive (+) enantiomer. Therefore the positive inotropic action mediated by beta receptor activation predominates.

  • Dobutamine does not activate dopamine receptors and therefore does not increase renal blood flow.

  • Because of its vasodilator properties, dobutamine's positive inotropism is accompanied by a decrease in afterload. For this reason dobutamine is favored over dopamine for most advanced heart failure patients who have not improved with digoxin, diuretics, and vasodilator therapy.


  • Dopamine has limited utility in patents with left ventricular dysfunction. It often produces tachycardia which may increase left ventricular work.

  • Dopamine-induced vasodilation is mediated by direct stimulation of D1 and D2 post-synaptic dopamine receptors. Vasodilation of renal vasculature is noteworthy and may benefit patients with marginal GFR due to poor renal perfusion.


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