• Anaphylactic Shock: Epinephrine is the primary treatment for severe, life-threatening allergic reactions caused by insect bites/stings, food, or medications. It works rapidly by relaxing airway muscles (bronchodilation) to improve breathing and tightening blood vessels (vasoconstriction) to increase blood pressure, counteracting the effects of histamine released during an allergic reaction.
• Cardiopulmonary Resuscitation (CPR): It is a critical drug used to stimulate the heart and restore a normal rhythm and circulation during cardiac arrest.
• Local Anesthesia Adjunct: Epinephrine is sometimes added to local anesthetics to cause local vasoconstriction, which keeps the anesthetic confined to the injection site for a longer period and delays its absorption into the general circulation.
• Control Superficial Bleeding: A dilute solution of epinephrine may be applied topically (e.g., on gauze packing) to control minor bleeding in mucosal or subcutaneous tissues due to its potent vasoconstrictive properties. 

ADMINISTRATION

• Intramuscular (IM): The most common route for anaphylaxis treatment, as it provides rapid absorption.
• Subcutaneous (SC): An alternative route for treating anaphylaxis, although absorption is slower than IM.
• Intravenous (IV): Typically used in critical hospital settings, such as during CPR or for continuous infusions to manage severe hypotension, to ensure the most rapid effect.
• Endotracheal: An alternative route during CPR if intravenous access cannot be immediately established.