For Helicobacter pylori eradication, regimens involving high-dose metronidazole (Flagyl) are significantly more effective in geographic regions with high metronidazole resistance and for resistant strains.
Why this matters
Authors say no previous meta-analysis compared low- vs high-dose metronidazole for eradicating H pylori.
- No publication bias detected.
- 2 studies of low quality, 2 of high quality.
- Eradication rates for intention-to-treat and per-protocol analyses did not differ with high- vs low-dose therapies; range, 76%-85%.
- Eradication rates in regions with high metronidazole resistance (2 studies; nonheterogeneous):
- High-dose: 74% (48/68; 95% CI, 63%-85%);
- Low-dose: 52% (35/67; 40%-64%);
- Relative risk (RR), 1.40 (1.08-1.82; P=.01).
- Eradication of metronidazole-resistant strains (2 studies; nonheterogeneous):
- High-dose: 71% (27/38; 95% CI, 57%-85%);
- Low-dose: 46% (19/41; 31%-62%);
- RR, 1.50 (1.02-2.19; P=.04).
- Side effects (2 studies; nonheterogeneous) more likely in high-dose therapies (RR, 1.84; 95% CI, 1.17-2.88; P=.008).
- No significant adherence differences (4 studies; nonheterogeneous).
- Systematic review, meta-analysis, 4 randomized controlled trials (1999-2006) comparing low- vs high-dose metronidazole in multidrug regimens for H pylori eradication (n=612).
- Outcomes: eradication rates, adherence, side effects.
- Funding: National Natural Science Foundation of China; Shanghai Jiao Tong University School of Medicine.
- Few, non-double-blinded studies.
- Heterogeneous for major eradication analyses.
- Several well-designed non-English-language studies excluded.