US DOUBLE-BLIND, CONTROLLED TRIALS OF OMEPRAZOLE AND AMOXICILLIN FOR TREATMENT OF HELICOBACTER-PYLORI

Background: Widely variable Helicobacter pylori eradication rates have been reported with omeprazole/amoxycillin dual therapy. We present th e first US double-blind, controlled trials of this dual therapy. Metho ds: Three separate studies were performed: Studies 1 and 2 included pa tients with an active duodenal ulcer and Study 3 included patients wit h a documented history of duodenal ulcer. H. pylori eradication regime ns in all studies were omeprazole plus amoxycillin vs. omeprazole vs. amoxycillin for 2 weeks. Doses in Study 1 were omeprazole 40 mg b.d. a nd amoxycillin 500 mg t.d.s., and in Studies 2 and 3 they were omepraz ole 20 mg b.d. and amoxycillin 1 g t.d.s. Endoscopic biopsy tests were used for H. pylori diagnosis, and testing for H. pylori eradication w as done at least 4 weeks after the completion of therapy, Amoxycillin sensitivities were performed in Study 2. Results: intention-to-treat ( ITT) and per protocol (PP) analyses showed that eradication rates with omeprazole/amoxycillin [ITT: 39%, 40%, 46% (n = 72, 62, 48); PP: 50%, 46%, 54% (n = 54, 52, 37)] were significantly greater than monotherap y with either omeprazole (ITT: 0-4%: PP: 0-5%) or amoxycillin (ITT: 2- 5%; PP: 0-11%). No patients taking the dual therapy discontinued thera py due to adverse events. Amoxycillin resistance was not seen at basel ine (n = 76) or after amoxycillin therapy (n = 56). Conclusions: Omepr azole/amoxycillin dual therapy is well tolerated but the eradication r ate which can be expected in the USA is at best about 50%.