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The effect of dosing with omeprazole on the accuracy of the 13 C‐urea breath test in Helicobacter pylori ‐infected subjects
Author(s) -
Susan J. Connor,
Francis Seow,
Meng C. Ngu,
Peter Katelaris
Publication year - 1999
Publication title -
alimentary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.308
H-Index - 177
eISSN - 1365-2036
pISSN - 0269-2813
DOI - 10.1046/j.1365-2036.1999.00601.x
Subject(s) - omeprazole , helicobacter pylori , dosing , medicine , breath test , urea breath test , urea , helicobacter infections , gastroenterology , spirillaceae , pharmacology , nuclear medicine , helicobacter pylori infection , gastritis , biochemistry , chemistry
Background : The 13 C‐urea breath test ( 13 C‐UBT) is an accurate means of Helicobacter pylori diagnosis. However, proton pump inhibitors may suppress H. pylori and cause false negative results. Aim : To study the kinetics of H. pylori suppression by omeprazole during and after short‐term use. Methods : Volunteers underwent a baseline 13 C‐UBT ( 13 C‐urea 100 mg). H. pylori ‐positive subjects took omeprazole 20 mg daily for 14 days. Those who remained 13 C‐UBT positive (δ 13 CO 2 ≥ 5) continued omeprazole for a further 14 days. 13 C‐UBTs were performed weekly on omeprazole and then every second day after it was stopped. False negatives occurred when δ 13 CO 2 fell to < 5. Results : In 25 H. pylori ‐positive subjects (mean age 43.9 ± 2.4 years; 21 females, 4 males) the mean baseline δ 13 CO 2 was 28.1 ± 3.4. False negative breath tests occurred in three subjects after 7 days of omeprazole and in a further four subjects after 14 days. A further six subjects developed negative tests between Days 14 and 28. Following cessation of omeprazole, the 13 C‐UBT became positive again in 12/13 subjects within 4 days and in all within 6 days, with a mean recovery to 99.9 ± 18.6% of baseline δ 13 CO 2 . Conclusions : False negative 13 C‐UBTs are common during treatment with omeprazole and occur after as little as 7 days. Return to positive test results is rapid after cessation of omeprazole. These findings are relevant to the timing of testing in clinical practice.