What is the primary function of diphenhydramine in allergic reactions?

Diphenhydramine is primarily an antihistamine used to counteract the symptoms of allergic reactions. Its primary function in this context is to block histamine receptors, which helps to alleviate symptoms such as itching, hives, and swelling associated with allergic responses. While the drug does have sedative properties and can help with nausea, these are not its primary roles in treating allergic reactions.

When an allergic reaction occurs, especially in severe cases like anaphylaxis, epinephrine is often the first-line treatment due to its rapid action in alleviating symptoms related to airway constriction and cardiovascular collapse. Diphenhydramine serves an important role as an adjunct to epinephrine by further assisting in the management of allergic symptoms. It does not prevent wheezing directly, but by alleviating the overall allergic response, it can contribute to reducing bronchospasm in conjunction with epinephrine. This collaborative approach enhances the effectiveness of the treatment protocol during an allergic reaction.