title: Variability with omeprazole-amoxicillin combinations for treatment of Helicobacter pylori infection.
abstract: OBJECTIVE
  Although omeprazole co-therapy enhances the effectiveness of some antimicrobials for the treatment of Helicobacter pylori infection, results have not been uniform. A meta-analysis suggested that 20 mg of omeprazole b.i.d. and 2 g or more of amoxicillin would yield a > 80% success rate (Gastroenterology 1994; 106: 142A). Our objective in this study was to test that hypothesis.
  
  
  METHODS
  Volunteers with H. pylori infection were studied. Anti-H. pylori therapy was administered with meals for 14 days (omeprazole 20 mg b.i.d. plus amoxicillin 1 g t.i.d., or omeprazole 20 mg b.i.d. plus amoxicillin 0.5 g t.i.d.). Endoscopy was performed 4-6 wk after antimicrobial therapy ended, and the presence or absence of H. pylori was determined with biopsy specimens by Genta stain.
  
  
  RESULTS
  Fifty-nine volunteers completed the study; 30 were studied twice. The overall success for initial treatment with either combination of amoxicillin and omeprazole was 18 of 59 [30.5%; 95% confidence interval (CI) = 19-44%]. The success rate with 500 mg amoxicillin t.i.d. was 7 of 29 (24%; 95% CI = 10-43%). With 1 g t.i.d. amoxicillin, the cure rate was higher (36.6%) (11 of 30; 95% CI = 20-56%), or intention-to-treat result was 11 of 31 (35.4%), which includes the early dropout. Compliance was > 95% for both therapies. Side effects were experienced by eight patients, two receiving 1.5 g amoxicillin and six receiving 3 g amoxicillin (p > 0.2). German trials suggest that better results might be achieved when amoxicillin is given as suspension while fasting. Thirty treatment failures were re-treated with 1 g amoxicillin suspension t.i.d., given fasting, and omeprazole 20 mg b.i.d. The cure rate was 16.6% (95% CI = 6-35%).
  
  
  CONCLUSIONS
  Amoxicillin/omeprazole combinations for treatment of H. pylori infection do not yield consistent results. The reason is unknown, but the reported high rate of success with 40 mg of omeprazole and 750 mg t.i.d. suggests that almost complete inhibition of acid secretion is necessary to obtain consistent results with this combination.
authors.affiliation: Department of Medicine, Veterans Affairs Medical Center, Houston, Texas, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Graham
authors.forename: H
authors.initials: H
authors.lastname: Malaty
authors.forename: H M
authors.initials: HM
authors.lastname: el-Zimaity
authors.forename: R M
authors.initials: RM
authors.lastname: Genta
authors.forename: R A
authors.initials: RA
authors.lastname: Cole
authors.forename: M T
authors.initials: MT
authors.lastname: al-Assi
authors.forename: M M
authors.initials: MM
authors.lastname: Yousfi
authors.forename: G A
authors.initials: GA
authors.lastname: Neil
authors.forename: D Y
authors.initials: DY
authors.lastname: Graham
mesh_terms: D000328:Adult; D000658:Amoxicillin / Q000008:administration & dosage*; D001706:Biopsy; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D005756:Gastritis / Q000188:drug therapy / Q000382:microbiology*; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D009853:Omeprazole / Q000008:administration & dosage*; D010349:Patient Compliance; D017211:Treatment Failure
chemical_list: D000658:Amoxicillin; D009853:Omeprazole