dobutamine

Dobutamine is a synthetic catecholamine used as a short-term inotropic agent to support cardiac output in patients with heart failure or cardiogenic shock. It is administered by intravenous infusion in hospital settings, with dosing titrated to achieve target hemodynamic effects.

Mechanism and effects: Dobutamine acts predominantly as a beta-1 adrenergic receptor agonist, increasing cyclic AMP in cardiac myocytes to enhance contractility (inotropy) and stroke volume. It has some beta-2 activity and little or no alpha-adrenergic activity, which tends to produce a rise in cardiac output with only modest changes in systemic vascular resistance. This can result in improved forward blood flow while avoiding excessive vasoconstriction.

Administration and pharmacokinetics: Dobutamine is given by continuous IV infusion, typically in an intensive care or monitored acute-care setting. The dose is adjusted to optimize cardiac output and blood pressure. It has a very short half-life, around 2 minutes, and its effects dissipate quickly if the infusion is stopped. It is metabolized mainly by catechol-O-methyltransferase and monoamine oxidase, with renal and hepatic clearance contributing to elimination.

Side effects and safety: Common adverse effects include tachycardia and arrhythmias, which can provoke or worsen myocardial ischemia in patients with coronary disease. Chest pain, headaches, and fluid retention may occur. Dobutamine should be used with caution in patients with tachyarrhythmias, severe aortic stenosis, or uncorrected hypovolemia, and ongoing monitoring of heart rate, rhythm, blood pressure, and perfusion is recommended. It is generally avoided for long-term use due to arrhythmia and ischemia risk.

Clinical uses: Indicated for acute decompensated heart failure or cardiogenic shock where an increase in cardiac output is required, typically as a bridge to recovery, device therapy, or further intervention.