title: 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 Helicobacter pylori (H. pylori) infection while they are taking proton pump inhibitors. The aim of this study was to determine: (i) if the decreased sensitivity of the urea breath test during proton pump inhibitor is corrected by different techniques for breath testing and (ii) if the sensitivity of stool test is decreased with the administration of proton pump inhibitors.
  
  
  METHODS
  Prospective randomized single-blind study was performed in a tertiary care university hospital. Out of 72 H. pylori infected patients endoscoped for upper abdominal symptoms 48 were randomized to proton pump inhibitors (omeprazole 20 mg each day or esomeprazole 40 mg each day) and 24 to antacid (aluminum hydroxide 800 mg each day) for 14 days. Several breath tests (standard 75 mg (13)C-UBT with citric acid, with orange juice, a tablet breath test with 100 and 50 mg of (13)C), and a stool test were carried out. Baseline samples were collected before and after treatment.
  
  
  RESULTS
  The baseline sensitivity for all breath tests was 100% in both groups; for stool test it was 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 low (UBTs range: 77.1%-85.4%; stool test: 83%; 95% CI: 63.9-91.1), while 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.
authors.affiliation: Department of Internal Medicine and Gastroenterology, University of Bologna, S. Orsola Halpighi Hospital, Bologna, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Gatta
authors.forename: Nimish
authors.initials: N
authors.lastname: Vakil
authors.forename: Chiara
authors.initials: C
authors.lastname: Ricci
authors.forename: John F
authors.initials: JF
authors.lastname: Osborn
authors.forename: Andrea
authors.initials: A
authors.lastname: Tampieri
authors.forename: Federico
authors.initials: F
authors.lastname: Perna
authors.forename: Mario
authors.initials: M
authors.lastname: Miglioli
authors.forename: Dino
authors.initials: D
authors.lastname: Vaira
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000536:Aluminum Hydroxide / Q000008:administration & dosage*; D000863:Antacids / Q000008:administration & dosage; D001944:Breath Tests / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D064098:Esomeprazole; D005243:Feces / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000008:administration & dosage*; D011446:Prospective Studies; D054328:Proton Pump Inhibitors; D012016:Reference Values; D016037:Single-Blind Method; D016896:Treatment Outcome; D014508:Urea
chemical_list: D000863:Antacids; D054328:Proton Pump Inhibitors; D000536:Aluminum Hydroxide; D014508:Urea; D009853:Omeprazole; D064098:Esomeprazole