Inotrope · Catecholamine
Dobutamine
Indications
- Short-term inotropic support for low output from depressed contractility (label): decompensated heart failure, cardiogenic shock once MAP is supported
- Septic shock with hypoperfusion from myocardial dysfunction despite adequate volume and MAP (SSC)
- Low output after cardiac surgery, and RV failure after volume loading
- Bridge to transplant or mechanical support, or palliative home infusion (off-label)
- Pharmacologic stress echocardiography (off-label)
Dosing
Dobutamine drip card and mL/h converterStart: 2–5 mcg/kg/min (label starts 0.5–1)
Mechanism of action
Dobutamine is a synthetic catecholamine that acts mainly on β1 receptors: Gs-coupled adenylyl cyclase raises cAMP, and protein kinase A phosphorylates L-type calcium channels, phospholamban and troponin I, so contraction strengthens and relaxation speeds. It is racemic: the (+) isomer is a β1 and β2 agonist and α1 antagonist, the (−) isomer an α1 agonist, so vascular α1 and β2 effects largely cancel, leaving inotropy with mild vasodilation. It neither releases norepinephrine nor acts on dopamine receptors.
Pharmacology
- Cardiovascular: raises stroke volume and cardiac output and lowers wedge pressure and SVR; heart rate rises less than with isoproterenol, though by 30 bpm or more in 10% (label)
- Cardiovascular: speeds AV conduction (faster ventricular rate in AF) and raises myocardial O₂ demand, the basis of stress echocardiography
- Cardiovascular: BP may fall with hypovolemia (β2 vasodilation) or rise; systolic rose 50 mm Hg or more in 7.5% (label)
- Renal: urine output rises only through better cardiac output (no D1 effect)
- Metabolic: β2 shifts K⁺ into cells (hypokalemia)
- Other: tolerance after about 72 h as β receptors downregulate
Pharmacokinetics
| Onset | 1–2 min IV (label) |
|---|---|
| Peak | Up to 10 min (label) |
| Half-life | About 2 min (label; 2.4 min in severe heart failure) |
| Distribution | Vd about 0.2 L/kg, larger with edema (Kates 1978) |
| Metabolism | COMT methylation to inactive 3-O-methyldobutamine, and conjugation (label) |
| Clearance | About 2.4 L/min/m² (Kates 1978) |
| Elimination | Urine, as conjugates of dobutamine and 3-O-methyldobutamine (label) |
Chemistry
- Synthetic catecholamine: dopamine with a bulky 3-(4-hydroxyphenyl)-1-methylpropyl group on the amine, which adds β1 selectivity and removes indirect action; no β-hydroxyl
- One chiral center, given racemic because the enantiomers' opposing α1 actions balance (Ruffolo 1987)
- Premixed 1, 2 or 4 mg/mL in D5W with sodium metabisulfite and edetate, pH 2.5–5.5 (label)
- A pink tint from slight oxidation does not mean lost potency (label); do not mix with sodium bicarbonate or other strong alkalis
Adverse effects and cautions
In the one-pagers
- Vasopressors and InotropesReceptors and effects: Dobutamine: β1 > β2: ↑ / ↑↑ / ↓
- ACS and STEMIMechanical complications, RV infarction and shock: RV infarction accompanies up to 40% of inferior STEMIs (LITFL). V4R elevation marked 31% vs 6% in-hospital mortality (Zehender 1993) and fades within 10 h in half of patients. Expect hypotension, clear lungs and raised JVP, with RAP ≥10 mm Hg close to the wedge (RAP:PCWP ≥0.8). Reperfuse; no nitrates or diuretics; fluid in 250–500 mL steps while o
- Obstetric EmergenciesAmniotic fluid embolism: Right heart failure: echo, 500 mL boluses with reassessment, norepinephrine, adding dobutamine 2.5–5 or milrinone 0.25–0.75 mcg/kg/min
- Pulmonary EmbolismSupporting the failing RV: Dobutamine for low output once MAP holds; inhaled NO or epoprostenol as a bridge
- Shock Types at a GlanceCardiogenic shock: LV, RV, SCAI and MCS escalation: RV shock follows RV infarct (inferior STEMI, ST elevation in V4R), PE, ARDS, pulmonary hypertension and LVAD implantation. The dilated RV pushes the septum into the LV, so LV filling falls even with normal LV muscle. Give fluid until CVP is about 10–15 mm Hg, then stop; keep AV synchrony (pace heart block); avoid hypoxemia, hypercapnia, acidosis
- LVAD BasicsSelection, implant and the early postoperative course: The first week is about the right ventricle. Unloading pulls the septum leftward and removes its help to RV contraction while pump flow raises venous return to an RV still facing high pulmonary pressures; it dilates, the LV under-fills, and flow and PI fall with a high CVP. INTERMACS counts right heart failure as needing an RVAD, prolonged inh
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Sources
- FDA label: dobutamine in dextrose (2026)
- Kates and Leier 1978 (kinetics)
- Ruffolo 1987 (enantiomers)
For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow your local protocols and medical direction.