vasopressors
Summary
Drugs that raise blood pressure primarily by causing vasoconstriction, used in shock when fluid resuscitation alone is insufficient. Norepinephrine is first-line in most forms of shock, especially septic shock.
Detail
Norepinephrine: potent alpha-1 agonist with modest beta-1, raises MAP with minimal tachycardia; first-line in septic, cardiogenic, and most undifferentiated shock. Epinephrine: alpha-1, beta-1, beta-2; first-line in anaphylaxis and cardiac arrest, second-line in septic shock. Phenylephrine: pure alpha-1 agonist, causes reflex bradycardia, useful for hypotension with tachyarrhythmia. Vasopressin (ADH analog): V1-receptor vasoconstriction independent of catecholamines, often added to norepinephrine in refractory septic shock. Dopamine: dose-dependent (low - dopaminergic, medium - beta-1, high - alpha-1); fallen out of favor due to arrhythmias. Dobutamine is an inotrope, not a true vasopressor (beta-1 selective). All cause peripheral ischemia and should be given through a central line when possible.
Sources
- First Aid for USMLE Step 2 CK
- Sketchy Pharm
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