What is the first drug that should be administered in cases of anaphylactic shock?

In the management of anaphylactic shock, the primary and first-line treatment is the administration of epinephrine. This drug acts quickly to counteract the severe allergic reactions by causing vasoconstriction, which raises blood pressure, and bronchodilation, which helps relieve symptoms of respiratory distress. Epinephrine also reduces vascular permeability, which can mitigate the swelling and hives associated with anaphylaxis.

While corticosteroids and antihistamines can be important in the overall management of anaphylactic reactions, they do not work as rapidly as epinephrine. Corticosteroids may help to reduce inflammation and prevent a delayed reaction but do not provide immediate relief from acute symptoms. Antihistamines can provide symptomatic relief but do not address the life-threatening aspects of anaphylaxis such as airway compromise and cardiovascular collapse.

Beta-blockers are often contraindicated in the setting of anaphylaxis because they may prevent the action of epinephrine and can worsen the situation. Thus, the best and most effective first choice in dealing with anaphylactic shock is epinephrine, as it specifically targets the critical physiological responses that must be managed urgently.