Basic Neuroscience · Neuropharmacology
Vasopressors & Inotropes
Vasopressors and inotropes — dose, mechanism, and hemodynamic + neuro effects. Verify doses against your institutional protocol before use.
| Medication | Dose | MOA | BP | HR | ICP | Cerebral vessels | SVR | Use | Adverse |
|---|---|---|---|---|---|---|---|---|---|
| Norepinephrine (Levophed) | 0.01–3 mcg/kg/min | α + β1 agonist (α>β) | ↑↑ | ↔/↓ | ↔ | Minimal direct (BBB) — maintains CBF via ↑CPP | ↑↑ | 1st-line septic & most shock; CPP augmentation | Reflex bradycardia, peripheral/digital ischemia |
| Phenylephrine (Neosynephrine) | 0.5–6 mcg/kg/min | Pure α agonist | ↑ | ↓ | ↔ | Minimal direct — safe for CPP support | ↑↑ | Neurogenic shock, tachyarrhythmia, maintain CPP | Reflex bradycardia, ↓cardiac output |
| Vasopressin | 0.01–0.07 U/min (usual 0.03; fixed adjunct) | V1 (vascular), V2 (renal) | ↑ | ↔ | ↔ | Cerebral vasoconstriction | ↑↑ | Catecholamine-sparing adjunct in septic shock | Peripheral/splanchnic/coronary ischemia, hyponatremia |
| Dopamine | 2–20 mcg/kg/min | Dose-dependent: DA → β1 → α | ↑ | ↑ | ↑ | Vasodilation → ↑cerebral blood volume | ↑ | Shock, symptomatic/resistant bradycardia | Tachyarrhythmia, tissue ischemia/gangrene (high dose) |
| Dobutamine | 2–20 mcg/kg/min | β1 > β2 agonist | ↔/↓ | ↑ | ↔ | Minimal | ↓ | Cardiogenic shock, low cardiac output (inotrope) | Hypotension, tachyarrhythmia, myocardial ischemia |
| Epinephrine | 0.05–2 mcg/kg/min (shock) | α + β (β low dose, α high) | ↑↑ | ↑↑ | ↑ | ↑CBF / cerebral metabolism | ↑ | Anaphylaxis, cardiac arrest, refractory shock | Tachyarrhythmia, hyperglycemia, lactic acidosis |
| Angiotensin II (Giapreza) | Start 20 ng/kg/min (max 80 ×3 h, then 40) | AT1 receptor agonist | ↑ | ↔ | ↔ | Vasoconstriction | ↑↑ | Distributive/vasodilatory shock refractory to catecholamines + vasopressin | Thromboembolism / VTE (give prophylaxis) |
| Inodilator — LOWERS blood pressure (not a pressor) | |||||||||
| Milrinone (Primacor) | 50 mcg/kg load, then 0.375–0.75 mcg/kg/min | PDE-3 inhibitor (inodilator) | ↓ | ↔/↑ | ↔ | Vasodilator — used for cerebral vasospasm (IV or intra-arterial) | ↓ | Low-output heart failure; cerebral vasospasm (SAH) | Hypotension (caution), arrhythmia; renal-adjust |
Light-blue rows = preferred pressors in neuro patients (minimal direct cerebral effect, maintain CPP). ↑ increase · ↓ decrease · ↔ little/no effect.
Drug of choice — General ICU
| Condition | Agent |
|---|---|
| Septic shock | Norepinephrine → add Vasopressin → add Epinephrine |
| Cardiogenic shock | Norepinephrine + Dobutamine |
| Heart failure (low output) | Dobutamine or Milrinone |
| Anaphylactic shock | Epinephrine → 2nd line Vasopressin |
| Undifferentiated hypotension | Phenylephrine or Norepinephrine |
Drug of choice — Neuro ICU
| Condition | Agent |
|---|---|
| Hemorrhagic stroke (ICH / SAH) | Norepinephrine (maintain CPP; avoid over-shoot) |
| Ischemic stroke (induced HTN / augmentation) | Phenylephrine or Norepinephrine |
| Cerebral vasospasm (SAH) | Norepinephrine / Phenylephrine (induced HTN) + Milrinone (IV / intra-arterial) |
| Neurogenic shock (spinal cord injury) | Norepinephrine or Phenylephrine (+ atropine/dopamine if bradycardic) |
Neuro.Wiki by Ahmed Koriesh, MD — Educational only, not a substitute for clinical judgement