A 52-year-old man with severe hypotension and bradycardia due to septic shock is started on an infusion. The agent chosen has α1 and β1 agonist activity but minimal β2 effects. Which drug was most likely selected?

Explanation

## Norepinephrine in Septic Shock **Key Point:** Norepinephrine is the **first-line vasopressor** in septic shock (per Surviving Sepsis Campaign guidelines) because it provides potent α1-mediated vasoconstriction (restoring blood pressure) combined with β1-mediated inotropic support (maintaining cardiac output) while avoiding excessive β2-mediated vasodilation. **High-Yield:** In septic shock, the goal is to restore mean arterial pressure (MAP ≥65 mmHg) and organ perfusion. Norepinephrine achieves this without the tachycardia and arrhythmia risk associated with high-dose epinephrine or dopamine. ## Adrenergic Agonist Selection in Shock States | Agent | α1 | β1 | β2 | Preferred Shock Type | Mechanism | |-------|----|----|----|-----------------------|----------| | Norepinephrine | +++ | ++ | − | Septic, cardiogenic | Vasoconstriction + inotropy | | Epinephrine | +++ | +++ | +++ | Anaphylaxis, cardiac arrest | Broad spectrum; risk of tachycardia | | Dopamine (high) | +++ | +++ | ± | Refractory hypotension | Dose-dependent; splanchnic vasoconstriction | | Phenylephrine | +++ | − | − | Pure vasoconstriction needed | No inotropic support | **Clinical Pearl:** Norepinephrine's **minimal β2 activity** is actually an advantage in septic shock because β2-mediated vasodilation in skeletal muscle would worsen hypotension. The agent restores peripheral vascular resistance without causing reflex tachycardia or arrhythmias. **Mnemonic:** **NE = Norepinephrine for Excellent septic shock management** (α1 ↑ BP, β1 ↑ CO, minimal β2 = no unwanted vasodilation).