Which drug is commonly used to manage a severe allergic reaction?

The use of Diphenhydramine as an adjunct to epinephrine in managing a severe allergic reaction, such as anaphylaxis, is well supported by clinical guidelines. Epinephrine is the first-line treatment for anaphylaxis because it quickly reverses the symptoms by constricting blood vessels, dilating airways, and increasing heart output. However, while epinephrine addresses the acute symptoms effectively, it does not provide a complete resolution of the allergic response.

Diphenhydramine, an antihistamine, can help alleviate additional symptoms of an allergic reaction, such as hives, itching, or swelling, which may occur after the initial epinephrine administration. This combination of medications allows for a comprehensive treatment plan that targets both the immediate and subsequent manifestations of a severe allergic reaction.

In contrast, solely using adrenaline without support from an antihistamine may leave some symptoms unaddressed. Medications like cinnarizine, which is primarily an antihistamine used to treat motion sickness, and promethazine, which is also an antihistamine but is not a first-line treatment for severe allergic reactions, do not have the same efficacy in handling anaphylaxis as the combination of epinephrine and diphenhyd