Which drug is first-line for anaphylaxis management?

• A. Buccal midazolam
• B. Adrenaline
• C. Glucagon
• D. GTN spray

Answer: (B)

Anaphylaxis requires rapid reversal of airway swelling, bronchoconstriction, and circulatory collapse. Adrenaline is the first-line treatment because it delivers both alpha- and beta-adrenergic effects that address all three problems at once. Its alpha-adrenergic action constricts dilated blood vessels, reducing mucosal edema and helping raise blood pressure, while its beta-adrenergic action bronchodilates the airways and reduces mediator release from mast cells. The heart is supported by beta-adrenergic stimulation, improving perfusion during the crisis.

In practice, give adrenaline as an intramuscular injection of a 1:1000 solution into the mid-outer thigh as soon as anaphylaxis is suspected. Adults typically receive 0.5 mg, with children dosed at about 0.01 mg/kg up to a maximum of 0.3 mg; the dose can be repeated every 5–15 minutes if symptoms persist. After administration, seek emergency help if not already on scene, provide high-flow oxygen, and monitor the patient closely. Elevate the legs if tolerated and consider IV fluids for hypotension; escalate to hospital-based treatment if there is no adequate improvement.

Other drugs shown in the options do not address the life-threatening airway and circulatory issues seen in anaphylaxis: for example, a benzodiazepine might help with anxiety or seizures but does not reverse the reaction; glucagon is used for specific overdose situations, not first-line anaphylaxis; nitrates are for chest pain, not this emergency.