Metronidazole, ranitidine and clarithromycin combination for treatment of Helicobacter pylori infection (modified Bazzoli's triple therapy).

BACKGROUND

Multi-drug regimens are generally required to reliably cure Helicobacter pylori infection. Metronidazole, clarithromycin and omeprazole has proven to be an effective combination therapy with a cure rate of 90% or greater.

METHODS

We evaluated a 14-day combination regimen for H.pylori infection consisting of metronidazole 500 mg b.d., clarithromycin 250 mg b.d. and ranitidine 300 mg b.d. (MRC) instead of omeprazole. Ranitidine alone was continued for an additional 4 weeks. H. pylori status was determined by rapid urease testing, histopathology using the Genta stain, and by culture at entry and 4 weeks after completing antimicrobial therapy.

RESULTS

Twenty-seven patients with documented peptic ulcer disease and H. pylori infection were treated. Five had previously failed macrolide-based antimicrobial therapy; none had received metronidazole. All ulcers were healed at week 6 except one patient taking naproxen; his H. pylori infection was cured. Overall, H. pylori infection was cured in 78% (95% CI = 58-91%). In patients with clarithromycin-sensitive isolates, the cure rate was 20 of 23 (87%, 95% C.I. = 66-97%); only one of four patients (25%) with clarithromycin-resistant isolates was cured. In contrast, four of five patients with metronidazole-resistant isolates were cured (80%). In patients with isolates sensitive to both antibiotics, the cure rate was 16 of 18 (89%, 95% C.I. = 65-99%). Mild side effects were reported by 27%, including diarrhoea and altered taste. Compliance averaged 98%.

CONCLUSION

These results suggest that the combination of metronidazole, ranitidine and clarithromycin results in high cure rates in patients with clarithromycin-sensitive isolates. Omeprazole may not be required for Bazzoli's triple therapy; and large multicentre comparative trials are indicated.