SUMMARYBackground: The need to withhold acid suppression therapy while awaiting urea breath test results is a common clinical problem in symptomatic patients. It is unclear at present if the dose or type of proton pump inhibitor or the type of test meal govern the apparent masking effect of proton pump inhibitors on the urea breath test. Aim: To prospectively evaluate Helicobacter pylori detection rates during treatment with four different proton pump inhibitors, utilizing a high-dose citric acid-based 13 C urea breath test.

Background: Confirmation of Helicobacter pylori eradication by urea breath test (UBT) is currently performed 4–6 weeks after completion of therapy because of unacceptable false-negative results in UBTs performed earlier. Use of a high-dose citric acid test meal appears to enable accurate detection of H. pylori even during short term therapy with proton pump inhibitors. Aim: To evaluate if use of a high dose citric acid (4.0 g) test meal can decrease the interval required for confirmation of eradication after triple therapy. Methods: 233 patients positive for H. pylori were randomized to undergo UBT at 7 days or 14 days after triple therapy, and again at 6 weeks. The latter test was considered the gold standard test. Results: The UBT performed 6 weeks after the end of treatment found that 79.9% were cured. The same test 7 days after therapy found false-negative detection of H. pylori in 7.3% patients compared to 3.2% patients examined after 14 days. The sensitivity, specificity, positive and negative predictive values and accuracy for evaluation on day 14 were 80, 100, 100, 96.3 and 96.7%, respectively. Conclusions: High-dose citric acid-based UBT is a valid test for the assessment of H. pylori status 14 days after triple therapy. This may obviate the delay in instituting second-line eradication therapy, or further evaluation of the symptomatic patient unresponsive to therapy despite eradication.