Explain Why Adrenaline is used in Anaphylactic Shock

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Explain Why Adrenaline is used in Anaphylactic Shock

Explain why Adrenaline is used in Anaphylactic Shock. Anaphylaxis is a severe form of life threateing allergic reaction that causes swelling of  mouth and tongue, breathing problems, flushing, collapse and a loss of consciousness. Adrenaline is used as a treatment for anaphylaxis.


Adrenaline is the life saving drug for the treatment of anaphylactic shock. Adrenaline 0.3 – 0.5 ml of 1:1000 solution (1 mg/ml) is administered intramuscularly.

◙ Causative agents of Anaphylactic Shock : Anaphylaxis or anaphylactic shock can be triggered by these agents peanuts, shellfish, and insect bites or stings. These can cause severe anaphylactic reaction or allergic reaction lead to anaphylactic shock.

◙ Symptoms of Anaphylaxis :

►Vasodilation → Peripheral Resistance↓ → BP↓


►Hypotension – BP ↓

►Increased vascular permeability↑

►Activation of vagal pathways

◙ Mechanism of Action:

Adrenaline produces the following effect :

►ß1- medicated cardiac stimulation → HR↑ + FOC↑

►α1 – mediated vasoconstriction → Peripheral Resistance↑ →BP↑

►α1 – mediated vasoconstriction → Mucosal Oedema ↓

►ß2 stimulation → Bronchodilation + ↓Release of mediators from Mast cells

►Physiologic Antagonist of Histamine → ↓Release of mediators from Mast cells

That explains Why Adrenaline is used in Anaphylactic Shock.

Uses of Adrenaline as Treatment of Anaphylactic Shock:

A patient with a history of allergic attack should be considered for Adrenaline. This is available in the market as a auto-injector or pen. Administration of adrenaline on certain attack will eliminate the chances of death.

Type of medicine Sympathomimetic
Used for Anaphylactic Shock
Medicine Name Emerade®; EpiPen®; Jext®
Available as Auto-injection device or ‘pen’

Questions Type : Explain Why

Chapter : Autonomic Nervous System

Explain Why Adrenaline is used in Anaphylactic Shock.

Information can be seen from Essential of Medical Pharmacology by KDT and Shanbhag 

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