American Board of Family Medicine (ABFM) Practice Exam

A patient with a history of rash after penicillin use should be prescribed which of the following medications?

1. Amoxicillin/clavulanate (Augmentin)

2. Cefuroxime (Ceftin)

3. Doxycycline

4. Azithromycin (Zithromax)

The correct answer is: Cefuroxime (Ceftin)

In this scenario, the patient has a history of rash after using penicillin. It is crucial to understand the mechanisms of drug allergies and the potential for cross-reactivity among β-lactam antibiotics. Patients with a history of a non-severe allergic reaction, such as a rash, to penicillin may often tolerate other antibiotics that are structurally different from penicillin. Cefuroxime, which is a second-generation cephalosporin, is generally considered an alternative for patients with a non-severe penicillin allergy. While there is a risk of cross-reactivity between penicillins and cephalosporins due to their similar β-lactam structure, the overall risk of serious allergic reactions is considerably lower, particularly with second-generation cephalosporins like cefuroxime. Therefore, prescribing cefuroxime is appropriate in this context, as it addresses a bacterial infection while minimizing the risk of eliciting a severe allergic reaction in the patient. Meanwhile, amoxicillin/clavulanate (Augmentin) is a penicillin derivative and would typically be contraindicated in a patient with a known allergy to penicillin due to the high potential for an allergic response. Doxycycline, a tetracycline