Anaphylactic shock is treated with which of the following drugs?

AIIMS Bhatinda NO - 2019

Pharmacology

Easy

Appeared in: AIIMS Bhatinda NO - 2019

Explanation

Adrenaline (epinephrine) is the first-line, life-saving drug for treating anaphylactic shock.
It acts as a potent agonist at alpha and beta-adrenergic receptors, leading to three critical effects: vasoconstriction (which increases blood pressure), positive inotropic and chronotropic effects on the heart (which increases cardiac output), and bronchodilation (which opens the airways).
This multi-system action directly counteracts the life-threatening pathophysiology of anaphylaxis, including vasodilation, bronchoconstriction, and mucosal edema.
According to emergency guidelines, it should be administered intramuscularly in the thigh as soon as anaphylaxis is suspected for rapid absorption and action.

Option B: Propranolol is a non-selective beta-blocker. It is contraindicated in anaphylaxis because it can worsen bronchospasm and hypotension. Furthermore, it would block the beta-receptor effects of adrenaline, rendering the primary treatment less effective.
Option C: Enalapril is an Angiotensin-Converting Enzyme (ACE) inhibitor used for chronic conditions like hypertension and heart failure. It is not an emergency drug and its vasodilatory effects would worsen the hypotension of anaphylactic shock. A known side effect of ACE inhibitors is angioedema, which could mimic or exacerbate anaphylaxis.
Option D: Digoxin is a cardiac glycoside used to increase heart contractility and control the heart rate in conditions like heart failure and atrial fibrillation. It has no role in the management of anaphylaxis as it does not address the underlying allergic mechanisms like bronchoconstriction or vasodilation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological management of anaphylactic shock as background academic context rather than a clinical decision trigger.
A nurse's primary role is the rapid recognition of anaphylaxis (e.g., respiratory distress, hives, swelling, hypotension) and the immediate administration of intramuscular adrenaline.
After giving adrenaline, the nurse must continuously monitor the patient's blood pressure, heart rate, respiratory status, and oxygen saturation, and be prepared to administer further doses or initiate advanced life support.
Patient safety depends on having an anaphylaxis emergency kit readily available in all clinical settings, containing adrenaline, antihistamines, corticosteroids, and resuscitation equipment.

How to Approach the Question

First, identify the core clinical condition in the question stem: 'Anaphylactic shock'. This is a life-threatening emergency.
Next, recall the first-line, gold-standard treatment for this specific emergency. The immediate priority is to reverse the life-threatening symptoms.
Evaluate each option based on its drug class and primary mechanism of action.
Adrenaline (epinephrine) is the only drug listed that provides rapid vasoconstriction and bronchodilation, directly countering the effects of anaphylaxis.
Eliminate the other options by identifying their primary use: Propranolol (beta-blocker, contraindicated), Enalapril (ACE inhibitor for chronic HTN), and Digoxin (for heart failure). This confirms Adrenaline is the only appropriate choice.

Concept Tested & Keywords

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E6 Medicine Davidson Principles Practice 24e p. 224-226

E6 Pharmacology Nurses Shanbhag 3e p. 83-85