American Board of Internal Medicine (ABIM) Certification Practice Exam

In patients with a penicillin allergy, what H. pylori treatment regimen is recommended?

1. Clarithromycin, metronidazole, and omeprazole

2. Amoxicillin, levofloxacin, and clarithromycin

3. Clarithromycin, ciprofloxacin, and omeprazole

4. Metronidazole, clarithromycin, and levofloxacin

The correct answer is: Clarithromycin, metronidazole, and omeprazole

The recommended treatment regimen for patients with a penicillin allergy often includes the use of clarithromycin and metronidazole, along with a proton pump inhibitor such as omeprazole. This combination takes advantage of clarithromycin's effectiveness against H. pylori while avoiding beta-lactam antibiotics like amoxicillin, which are contraindicated in individuals with a penicillin allergy. Metronidazole provides additional efficacy against H. pylori, and the proton pump inhibitor is essential for creating an optimal pH environment in the stomach, enhancing the effectiveness of the antibiotics. This regimen is well-studied and recognized for effectively eradicating H. pylori in patients who cannot use penicillin. Other combinations listed, such as those with levofloxacin or ciprofloxacin, may be used in various contexts; however, they are typically not first-line or standard recommendations for patients with a penicillin allergy. The focus here is on safety and maximizing efficacy, which the selected regimen achieves by utilizing agents known to work well together against H. pylori while also being appropriate for a patient with penicillin allergy.