Anaes · Anaesthetic adjuncts

Dobutamine and dopamine

Also known as Beta-1 inotrope (dobutamine) · Dose-dependent dopamine · Synthetic and natural catecholamines · Renal-dose dopamine (disproven concept)

Dobutamine and dopamine are the two inotropic catecholamines most often paired in anaesthesia and intensive-care exams because they share a beta-1 inotropic core yet diverge sharply in their receptor breadth and their adverse-effect profile. DOBUTAMINE is a SYNTHETIC catecholamine whose dominant action is BETA-1 agonism, giving increased contractility and cardiac output while remaining VASODILATING at clinical doses (beta-2 offsets alpha-1, so systemic vascular resistance and pulmonary capillary wedge pressure fall — taught pharmacology); it causes less tachyarrhythmia than dopamine or adrenaline and is the prototypical inotrope for acute heart failure and cardiogenic shock, and the standard pharmacological stressor for dobutamine stress echocardiography (prognostic value reaffirmed in a 166-patient South African cohort, Dippenaar 2026). DOPAMINE is the natural precursor of noradrenaline and acts both directly and indirectly (the latter by releasing noradrenaline from sympathetic nerve terminals), and its exam-defining feature is DOSE-DEPENDENT receptor selectivity: LOW infusion doses (1 to 3 mcg per kg per min) recruit DOPAMINE-1 (D1) receptors causing renal and mesenteric vasodilation, MODERATE doses (3 to 10 mcg per kg per min) recruit BETA-1 giving inotropy, and HIGH doses (above 10 mcg per kg per min) recruit ALPHA-1 giving vasoconstriction (taught formulary tiers; the cited porcine cord-perfusion study owns no dosing claim — Routkevitch 2026). The historical low-dose renal-dose dopamine concept has been DISPROVEN in a 328-patient placebo-controlled trial: dopamine 2 mcg per kg per min did NOT move peak creatinine, creatinine over 300 micromol per L, dialysis need, length of stay or deaths (Bellomo 2000). Dopamine is more arrhythmogenic than dobutamine because its indirect noradrenaline release supercharges beta-1 stimulation, and it raises pulmonary vascular resistance (caution in pulmonary hypertension); both drugs share a short half-life of about 2 minutes (taught pharmacology), COMT metabolism, tachyphylaxis after 48 to 72 hours from beta-receptor downregulation (taught pharmacology), and extravasation necrosis reversed by phentolamine (cohort-exact: 31 of 3734 peripherally initiated patients, 0.8% — Shyu 2025). Dopamine is one of the compared first-line options in neonatal fluid-refractory septic shock with NO demonstrated superiority over alternatives (4-RCT null — Yahya 2026) and a historically entrenched agent for symptomatic bradycardia, while dobutamine is the cleaner pure inotrope and the stress-testing pharmacological agent; vasopressor-versus-delirium data in older adults show NO difference between phenylephrine and norepinephrine (OR 0.97, P 0.9065 — Dong 2026). Built on the prognostic dobutamine stress echocardiography study (Dippenaar 2026, prognostic scope only), the porcine spinal cord blood flow adrenergic-challenge study (Routkevitch 2026, cord-perfusion scope only — owns no dopamine dosing, renal or receptor-tier claim), the vasopressor selection and postoperative delirium study (Dong 2026, delirium-null scope only), the neonatal septic shock first-line vasopressor meta-analysis (Yahya 2026, 4-RCT null scope), the peripheral vasopressor safety cohort (Shyu 2025, extravasation scope), and the ANZICS low-dose dopamine renal trial (Bellomo 2000).

Checked against its sources on 11 Sept 2026