Dobutamine is a direct stimulator of β-adrenergic receptors and is generally considered a selective β1-adrenergic agonist. The mechanism of action of the drug is complex. The β-adrenergic action is thought to be due to stimulation of adenylate cyclase activity. At therapeutic doses, dobutamine has moderate β2- and α1-adrenergic agonist activity at receptors that is relatively stable and has minimal direct effects on systemic vasculature. The main effect of dobutamine at therapeutic doses is cardiac stimulation.