Dobutamine

Dobutrex

vasopressorIVOnset: 1–2 minutesDuration: Minutes; continuous infusion

Mechanism of Action

Synthetic catecholamine. Primarily beta-1 agonist (inotropic and chronotropic). Mild beta-2 effects (mild vasodilation). Negligible alpha effects — does NOT raise SVR.

Dosing

Adult

2.5–20 mcg/kg/min IV continuous infusion

Indications

Cardiogenic shock (low cardiac output, high filling pressures)
Acute decompensated heart failure
Stress echocardiography agent

Contraindications

Hypertrophic obstructive cardiomyopathy (HOCM)
Uncorrected hypovolemia
Idiopathic hypertrophic subaortic stenosis

Side Effects

Tachycardia
Tachyarrhythmias
Hypotension (due to beta-2 vasodilation)
Increased myocardial O2 demand
Hypokalemia

Monitoring Parameters

HR and ECG (arrhythmia)
Blood pressure
Cardiac output / CVP
Urine output

Drug Interactions

Beta-blockers (antagonize inotropic effect)
MAOIs (exaggerated cardiovascular response)

Clinical Pearls

INOTROPE — increases cardiac output without vasoconstriction (key distinction from dopamine at high doses)
May cause hypotension due to beta-2 vasodilation — combine with vasopressor if needed
Preferred inotrope in cardiogenic shock (e.g., decompensated CHF)
Does NOT substitute for norepinephrine in septic shock (no alpha effects)
Used in stress echo to increase cardiac demand and unmask ischemia

Mnemonic

💡 DOBUTamine: DO BooT Up the heart (inotrope — pumps harder, not harder BP)

NBRC High-Yield

Inotrope — increases cardiac contractility and output
Beta-1 dominant — NO alpha effects; does not raise SVR
Can cause HYPOTENSION (beta-2 vasodilation) — unlike dopamine at high doses
Use in cardiogenic shock; NOT for septic shock
Avoid in HOCM (dynamic outflow obstruction worsens)

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