Dobutamine

Dobutrex

Beta-1-selective synthetic catecholamine

Synthetic catecholamine with PREDOMINANT β1 activity (also β2, mild α1). Pure inotrope — increases contractility + heart rate (β1) with mild vasodilation (β2 + α1 balance). Does NOT release endogenous norepinephrine (unlike ephedrine).

Indications

•Cardiogenic shock with low cardiac output
•Acute decompensated heart failure
•Stress echocardiography (pharmacologic)
•Bridge to LVAD or transplant
•Septic shock with myocardial dysfunction (after norepinephrine)

Dosing

Context	Adult	Pediatric
Standard inotropic infusion	2.5-20 mcg/kg/min IV titrated to CO/MAP	—
Pediatric	(weight-based)	2.5-20 mcg/kg/min IV
Stress echo	5-40 mcg/kg/min IV in graded steps	—

Pharmacokinetics

Onset 1-2 min IV. Half-life ~2 min. COMT metabolism + renal excretion. Very predictable kinetics — easy to titrate.

Hemodynamic effects

↑Contractility, ↑HR (modest), ↑CO. BP variable — modest ↑MAP from increased CO offset by mild β2 vasodilation. ↓PVR. ↓SVR mildly.

Side effects

!Tachycardia (more than milrinone)
!Increased myocardial O2 demand (rate-related)
!Atrial + ventricular arrhythmias
!Tachyphylaxis with continuous infusion >72 h (β-receptor downregulation)
!Hypotension at very high doses (β2 dominates)

Contraindications

×Severe AS (relative)
×Hypertrophic obstructive cardiomyopathy
×Tachyarrhythmia
×Pheochromocytoma

Clinical pearls

★FIRST-LINE inotrope for cardiogenic shock when MAP adequate (need norepinephrine added if hypotension).
★Vs milrinone: SHORTER half-life (~2 min vs ~2 h) — easier to titrate, faster wash-out, more predictable. But more tachycardia/arrhythmia.
★Pulmonary HTN: less PVR reduction than milrinone — milrinone preferred for RV failure with high PVR.
★Sepsis: NOREPINEPHRINE first; ADD dobutamine if low CO + adequate MAP after norepi (Surviving Sepsis 2021).
★Stress echo: 5 mcg/kg/min start, increase q3 min to max 40 + atropine if HR doesn't reach 85% age-predicted.