CAMRT Radiography Practice Exam

A technologist is preparing contrast media for an enhanced CT scan of the chest for a patient with a known allergy to IV contrast media. What medication should be administered beforehand?

1. Diphenhydramine (Benadryl)

2. Hyoscine Butylbromide

3. Prednisone (corticosteroid)

4. Lorazepam

The correct answer is: Diphenhydramine (Benadryl)

In the scenario where a patient has a known allergy to IV contrast media, administering a medication beforehand is crucial for minimizing the risk of an allergic reaction during the enhanced CT scan. Diphenhydramine, commonly known as Benadryl, is an antihistamine that can help mitigate allergic responses by blocking histamine receptors. This makes it a suitable choice for premedication in cases where patients have a history of mild allergic reactions to contrast media. Using diphenhydramine may help alleviate symptoms like itching, hives, or mild anaphylactic reactions if they occur during the administration of contrast media. It is commonly administered in preparation for contrast-enhanced imaging studies to provide additional safety for patients with a known allergy. While corticosteroids, such as prednisone, may also be used for patients with more severe allergic histories and are often part of a premedication regimen for significant allergies, diphenhydramine serves as an effective first line for minor allergic reactions. Therefore, it can be a reasonable option, especially when used alongside strict monitoring. Other choices, such as hyoscine butylbromide, primarily target gastrointestinal spasms and do not address allergic reactions. Lorazepam is an anxiolytic that may help reduce anxiety