Dobutel Mechanism of Action

Pharmacology: Dobutamine is a sympathomimetic amine which has a strong stimulating effect on cardiac β₁ receptors and a weak effect on β₂- and α₁-receptors. The inotropic effect of dobutamine results from direct stimulation of cardiac β₁-receptors. It increases myocardial contractility, seldom induces a marked increase in heart rate (although tachycardia is occasionally observed), or arrhythmogenic or peripheral vascular effects.
Dobutamine exerts a dose-related, positive-inotropic effect at dose levels which do not significantly increase the heart rate. The risk of tachycardia and cardiac arrhythmia provoked by Dobutamine has proved to be relatively small. In patients with depressed cardiac output, stroke volume is also usually increased and systemic vascular resistance decreases.
Dobutamine is suitable for short-term inotropic support of the failing heart in patient with insufficient cardiac output and high left ventricular filling pressure but only slightly or moderately decreased blood pressure. Dobutamine is not suitable for monotherapy in severe hypotension or shock requiring vasopressor effect. In these patients, the result is probably obtained by using Dobutamine and dopamine concomitantly.
Pharmacokinetics: The onset of action of Dobutamine is within 2 minutes after instituting IV infusion. Peak plasma concentrations of the drug and peak effect occur within 10 minutes after initiation of IV infusion. The plasma half-life of Dobutamine is about 2 minutes.