PATIENTS: Patients selected had unequivocal evidence of H. pylori infection based on the urease test, culture and histology and had either peptic ulcer disease or non-ulcer dyspepsia.
DESIGN: The study was a comparative and double-blind study and patients were randomized to receive either amoxycillin 750 mg t.i.d. and metronidazole 500 mg t.i.d. for 12 days or amoxycillin 1000 mg b.i.d. and metronidazole 500 mg b.i.d. for 12 days. Both groups also received famotidine 40 mg for 6 weeks.
MAIN OUTCOME MEASURE: Patients were assessed for successful eradication, defined as absence of bacteria in all tests, at least 4 weeks after completion of antibiotic therapy by repeat gastroscopy.
RESULTS: One hundred and twenty-nine patients were recruited for the study. Two patients defaulted follow-up, two patients were withdrawn from the study and six patients were found to be non-compliant with medications. The eradication rates of the t.i.d. regimen was higher than the b.i.d. regimen (per protocol (PP) analysis: 83.3% (50/60) vs. 76.3% (45/59), P=0.337; intention-to-treat (ITT) analysis: 78.5% (51/65) vs. 75.0% (48/64), P=0.642). Seventy-five patients had pre-treatment cultures checked for metronidazole resistance, 33 (44.0%) were found to be resistant. Acquired resistance occurred in 3/40 (7.5%) patients. Eradication rates of metronidazole-sensitive and metronidazole-resistant patients: t.i.d. regimen - 100% (17/17) and 88.2% (15/17), b.i.d. regimen - 19/21 (90.5%) and 11/15 (73.3%). Side effects were reported in up to 70% of patients but were mild and tolerable in the majority. Two patients were withdrawn from the study because of a fixed drug eruption in one and generalized macular rash in the other.
CONCLUSION: Combination amoxycillin and metronidazole is effective in eradicating H. pylori. There was a tendency for the t.i.d. regimen to be better than the b.i.d. regimen and for metronidazole-resistant infections to be associated with a lower eradication rate but these differences did not reach statistical significance.
PATIENTS AND METHODS: Patients with unequivocal evidence of H. pylori infection based on culture, histology and rapid urease test of both antrum and corpus biopsies were recruited for the study. The study was a randomized, investigator-blind, comparative study. Patients received either omeprazole 20 mg o.m., clarithromycin 250 mg b.d. and amoxycillin 500 mg b.d. (OAC) or omeprazole 20 mg o.m., metronidazole 400 mg b.d. and clarithromycin 250 mg b.d. (OMC) for 1 week. Patients were assessed for successful eradication, which was defined as absence of bacteria in all tests (culture, histology and urease test on both antral and corpus biopsies), at least 4 weeks after completion of therapy.
RESULTS: Eighty-two patients were recruited for the study. Eradication rates on intention-to-treat analysis were--OAC: 36/41 (87.8%, 95% CI: 73.8, 95.9); OMC: 33/41 (80.5%, 95% CI: 65.1, 91.2). On per protocol analysis were--OAC: 36/40 (90%, 95% CI: 76.3, 97.2); OMC: 32/38 (84.2%, 95% CI: 68.7, 94.0). All side-effects encountered were mild and no patient discontinued treatment because of intolerance to medications. The most common side-effects were altered taste (OAC 31.7%, OMC 53.7%) and lethargy (OAC 14.6%, OMC 19.5%). Pre-treatment metronidazole resistance was encountered in 34/63 (54.0%) patients. No bacterial strains were found with primary resistance to clarithromycin. Metronidazole resistance did not significantly affect eradication rates. Emergence of resistance to clarithromycin was not seen post-therapy.
CONCLUSIONS: Both the OAC and the OMC regimens were convenient and well-tolerated treatments for H. pylori. However, eradication rates were lower than anticipated.