Effect of Proton Pump Inhibitors and Antacid Therapy on 13C-Urea Breath Tests and Stool Test for Helicobacter pylori Infection

Abstract Objective: There is uncertainty about the best method of testing patients for H pylori infection while they are taking proton pump inhibitors. The aim of this study was to determine: (1) if the decreased sensitivity of the urea breath test during proton pump inhibitor is corrected by different techniques for breath testing (2) if the sensitivity of stool test is decreased with the administration of proton pump inhibitors. Methods. Prospective, randomised single-blind study, performed in a tertiary care university hospital. 72 H pylori infected patients endoscoped for upper abdominal symptoms: 48 patients randomised to proton pump inhibitors (omeprazole 20mg each day or esomeprazole 40mg each day), and 24 to antacid (aluminum hydroxide 800 mg each day) for 14 days. Several breath tests (standard 75 mg 13C-UBT with citric acid, with orange juice, a tablet breath test with 100 and 50 mg of 13C) and a stool test were carried out. Baseline samples were collected before and after treatment. Results: The baseline sensitivity was for all breath tests 100% in both groups; for stool test 97.8% (95% CI: 88.7-96.6) and 90% (95%CI: 69.9-97.2) in the proton pump inhibitor and antacid group respectively. After treatment, the sensitivity of tests was significantly lower (UBTs range: 77.1%-85.4%; stool test: 83%; 95% CI: 63.9-91.1), whilst it was unchanged in the antacid group. Conclusions: False negative breath and stool tests are equally common in patients taking proton pump inhibitors. Antacids do not impair the sensitivity of the breath tests or the stool test