Which drug is commonly used for immediate relief of anaphylaxis?

Epinephrine is the drug commonly used for immediate relief of anaphylaxis due to its potent vasoconstrictive and bronchodilatory effects. When a person experiences anaphylaxis, their body undergoes a severe allergic reaction that can cause symptoms such as difficulty breathing, swelling, hives, and a drop in blood pressure. Administering epinephrine works quickly to reverse these symptoms by constricting blood vessels, thereby increasing blood pressure, and relaxing the muscles in the airways, which helps to alleviate respiratory distress.

Epinephrine is typically administered via an intramuscular injection, usually in the mid anterolateral thigh. This rapid action makes it a life-saving treatment in emergency situations when anaphylaxis occurs. The preferred formulation is often found in auto-injectors, making it accessible for people who are at risk of severe allergic reactions.

Options like Benadryl, while useful in treating allergic reactions, do not provide the rapid and effective treatment needed in anaphylaxis, as they primarily function as antihistamines and have delayed onset of action. Atropine and adrenaline, while they have their own clinical applications, are not the first-line treatments for anaphylactic emergencies like epinephrine is.