What is the first-line vasopressor in septic shock?

• A. Norepinephrine
• B. Epinephrine
• C. Dopamine
• D. Phenylephrine

Answer: (A)

In septic shock, after ensuring adequate fluid resuscitation, the goal is to restore mean arterial pressure by increasing systemic vascular resistance while preserving organ perfusion. Norepinephrine is the vasopressor of choice because it provides strong alpha-adrenergic vasoconstriction that raises vascular tone and MAP with relatively modest beta effects. This helps improve perfusion pressure without causing excessive heart rate or arrhythmias.

Dopamine historically was used, but it carries higher risks of tachyarrhythmias and inappropriate dose‑response, and outcomes with dopamine are not as favorable. Epinephrine can raise both blood pressure and cardiac output but its beta effects can lead to tachycardia, increased lactate, and more arrhythmias, so it is commonly reserved as an add-on or second-line option when norepinephrine alone is insufficient. Phenylephrine is a pure alpha-1 agonist that increases afterload without supporting cardiac output, which can worsen tissue perfusion in many septic patients, so it’s not preferred as the first-line choice.

Start norepinephrine to target a MAP around 65 mmHg, titrating to response.