Which medication is commonly used as an oral histamine blocker for delayed reactions?

Which medication is commonly used as an oral histamine blocker for delayed reactions?

• A. Diphenhydramine
• B. Epinephrine
• C. Prednisone
• D. Lorazepam

Answer: (A)

Histamine blockers work by blocking H1 receptors to reduce symptoms caused by histamine release in allergic reactions. For delayed reactions, taking an oral antihistamine helps relieve itching, hives, and swelling that develop after the reaction starts. Diphenhydramine is a classic oral H1 receptor antagonist that effectively counters these histamine-mediated symptoms, making it the typical choice for managing delayed reactions. Epinephrine is reserved for life-threatening anaphylaxis and isn’t a histamine blocker. Prednisone can help reduce inflammation but doesn’t provide rapid histamine receptor blockade. Lorazepam is a sedative, not used to treat histamine-related symptoms.

Histamine blockers work by blocking H1 receptors to reduce symptoms caused by histamine release in allergic reactions. For delayed reactions, taking an oral antihistamine helps relieve itching, hives, and swelling that develop after the reaction starts. Diphenhydramine is a classic oral H1 receptor antagonist that effectively counters these histamine-mediated symptoms, making it the typical choice for managing delayed reactions.

Epinephrine is reserved for life-threatening anaphylaxis and isn’t a histamine blocker. Prednisone can help reduce inflammation but doesn’t provide rapid histamine receptor blockade. Lorazepam is a sedative, not used to treat histamine-related symptoms.