A 16-year-old girl with a sulfa allergy should avoid which of the following antibiotics?

The correct answer is Trimethoprim-sulfamethoxazole (Bactrim) because it contains the sulfonamide component sulfamethoxazole. This is critical for patients with a sulfa allergy to avoid any medications that contain sulfonamide derivatives, as these can trigger allergic reactions.

Trimethoprim-sulfamethoxazole is a combination antibiotic frequently used to treat a variety of infections. However, for individuals with a known sulfa allergy, it poses a significant risk of hypersensitivity reactions, which can range from mild skin rashes to more severe manifestations such as Stevens-Johnson syndrome.

Other antibiotics listed, such as Ciprofloxacin, Amoxicillin, and Piperacillin-tazobactam, do not contain sulfonamide components and are generally considered safe for individuals with a sulfa allergy. Therefore, while it is important to be aware of the various categories and components of antibiotic classes when treating patients, avoiding sulfanomide-containing antibiotics like Trimethoprim-sulfamethoxazole is essential for those with a sulfa allergy to ensure their safety and well-being.