Effects of several oral medications on the results of the 14C‐urea breath test

OBJECTIVE: To explore the effects of several oral medications on the results of the 14C-urea breath test (UBT). METHODS: One hundred and twelve patients with chronic gastritis that had tested positive in a rapid urease test were enrolled in the present study and were randomly divided into six groups: 20 patients received 20 mg famotidine b.i.d., 16 patients received 30 mg lansoprazole q.d., 18 patients received 1000 mg sucralfate t.i.d., 20 patients received 50 mg teprenone t.i.d., 20 patients received 220 mg colloidal bismuth subcitrate b.i.d., and 18 patients received four tablets t.i.d. of wei-de-an, a traditional Chinese medicine. The 14C-urea breath test was performed before treatment, 7 days after beginning drug treatment and 7 days after the cessation of drug treatment. RESULTS: All medications, especially colloidal bismuth subcitrate, were influenced by the result of the UBT. Seven days after drug treatment, the negative conversion rate of the UBT was 45.0% (9/20) in the colloidal bismuth subcitrate group, 30.0% (6/20) in the famotidine group, 31.3% (5/16) in the lansoprazole group, 16.7% (3/18) in the sucralfate group, 5.0% (1/20) in the teprenone group and 27.8% (5/18) in the wei-de-an group. However, all values returned to positive again 1 week after withdrawal. The influence of famotidine on UBT was similar to that of lansoprazole (P > 0.05). There was no significant difference between the results of the first and the third UBT. CONCLUSIONS: The UBT is a reproducible, non-invasive method for identifying Helicobacter pylori, but many drugs can influence the result of the UBT, so it is necessary to suspend treatment with these drugs before carrying out the testing procedure.