Which vasopressor is first-line in the treatment of anaphylactic shock?

Epinephrine is the first-line vasopressor for the treatment of anaphylactic shock due to its potent effects on both alpha and beta-adrenergic receptors. Its action includes increasing heart rate, improving cardiac output, and causing vasoconstriction, which helps to elevate blood pressure. Additionally, epinephrine has bronchodilator effects, making it essential in reversing the severe respiratory distress associated with anaphylaxis.

When anaphylaxis occurs, it can lead to significant hypotension and airway obstruction. Epinephrine not only addresses the cardiovascular collapse but also alleviates the swelling and bronchospasm in the airways, making it particularly effective in this acute setting. The rapid onset of action is critical, as anaphylaxis can progress rapidly, leading to life-threatening situations.

Other vasopressors, such as norepinephrine, dopamine, and vasopressin, are not the first choice for anaphylactic shock because they do not provide the same comprehensive benefits that epinephrine does in terms of both vascular and bronchial response. Thus, for treating anaphylactic shock, epinephrine is the standard of care and is often administered immediately upon diagnosis.