The influence of in vitro, nitroimidazole resistance on the efficacy of nitroimidazole-containing anti-Helicobacter pylori regimens: A meta-analysis

OBJECTIVE: The aim of this study was to determine the influence of nitroimi dazole resistance (NIR) on the efficacy of treatment for Helicobacter pylor i (H. pylori) infections by meta-analysis of the world literature. METHODS: A MEDLINE search, a manual search of all major gastroenterological journals from 1993 to 1997, and abstracts of gastroenterological and H. py lori meetings from 1993 to 1997 were performed. All treatment studies using a nitroimidazole and providing data about the medication used, dose freque ncy, total daily dose, duration of treatment, and eradication results in re lation to NIR were included. Eradication had to be assessed by two biopsy-b ased tests or a urea breath test greater than or equal to 4 wk after treatm ent. Individual studies were pooled into groups according to the medication used and the duration of treatment. The pooled estimate of the odds ratio (OR) of NIR for treatment failure and its 95% confidence interval (95% CI) were calculated for each group using the legit method. To detect any possib le bias, funnel plots (plots of effect estimates against sample size) were constructed. RESULTS: A total of 91 treatment arms, including a total of 4823 patients, were evaluated. The pooled ORs of NIR for treatment failure (95% CI) of pro tonpump inhibitors, bismuth, and quadruple regimens were 5.2 (3.8-7.1), 5.9 (4.1-8.3), and 7.0 (3.1-16.0), respectively. Eradication rates were 90% in susceptible strains but <75% in resistant strains. In susceptible strains, neither treatment duration nor the choice of the second antibiotic influen ced efficacy. In resistant strains, tetracycline was more effective than am oxicillin (bismuth regimens), and the longer the duration of regimens (bism uth-amoxicillin regimens) the more effective they were. Only quadruple regi mens given for greater than or equal to 1 wk were effective in resistant st rains. CONCLUSIONS: NIR decreases treatment efficacy. Treatment duration and choic e of other drugs influence the impact of NIR on treatment efficacy. If NIR is present, a nitroimidazole-containing regimen should be avoided or a quad ruple regimen should be given for >1 wk. (Am J Gastroenterol 1999;94:1751-1 759. (C) 1999 by Am. Coll. of Gastroenterology).