American Board of Internal Medicine (ABIM) Certification Practice Exam

How long should PPIs be avoided before conducting the urea breath test or fecal antigen test?

1. 3-5 days

2. 7-14 days

3. 2-4 weeks

4. 1 month

The correct answer is: 7-14 days

Proton pump inhibitors (PPIs) are known to suppress gastric acid secretion, which can impact the accuracy of tests used for the diagnosis of Helicobacter pylori infection, such as the urea breath test and fecal antigen test. These tests rely on the presence of active H. pylori bacteria and their interaction with gastric acid, which can be masked by the use of PPIs. It is generally recommended to avoid taking PPIs for a duration of 7-14 days prior to conducting these tests. This time frame allows for the gastric acid levels to return to baseline, thus ensuring that any active H. pylori present can be detected appropriately. During this period, the patient is encouraged to have the PPI discontinued so that the tests can provide a more accurate assessment of the presence of H. pylori. Choosing this specific duration balances the need for adequate acid recovery without unnecessary delays in diagnosis. Shorter durations, while they may allow some recovery, might still leave the gastric environment altered enough to lead to false-negative results. Inappropriate durations, like too brief or excessively long periods without PPIs, could either not allow enough time for accurate test results or could delay necessary treatment for H. pylori infection if testing is postponed unnecessarily.