Different effects of short-term omeprazole, lansoprazole or pantoprazole on the accuracy of the 13C-urea breath test

Background: Proton pump inhibitors may interfere with the accuracy of the C-13-urea breath test, but little information is available on the effect of standard doses of various proton pump inhibitors on this test. Aim: To evaluate the effect of short-term standard doses of omeprazole, lansoprazole and pantoprazole on the accuracy of the standardized C-13-urea breath test. Methods: A total of 124 patients with Helicobacter pylori, infection, diagnosed on the basis of gastric histology, rapid urease test and C-13-urea breath test, were studied. These patients received omeprazole, 20 mg/day, lansoprazole, 30 mg/day, or pantoprazole, 40 mg/day, for 2 weeks according to a randomized protocol. C-13-Urea breath test was repeated on days 4, 7 and 14 while on therapy and 7 days after proton pump inhibitor withdrawal. Results: Of the patients receiving omeprazole and lansoprazole, 30% (12/40) and 20% (8/41). respectively, became C-13-urea breath test negative during therapy, compared with none of the 42 patients treated with pantoprazole (P < 0.05). All the false negative C-13-urea breath test results returned to positive within 1 week of drug withdrawal, with a mean recovery to 84.7 +/- 15.6% of baseline δ(CO2)-C-13. Conclusions: Short-term omeprazole and lansoprazole interfere with the C-13-urea breath test, although a return to positive test results invariably occurs within 1 week of proton pump inhibitor withdrawal. In contrast, the accuracy of the C-13-urea breath test does not appear to be significantly impaired by short-term pantoprazole, which therefore may not necessarily be withdrawn before this test.