Clarithromycin, a new and well tolerated,
acid stable
macrolide antibiotic, has a similar antimicrobial spectrum to
erythromycin but a better in vitro MIC90 (0.03 microgram/l-1) against Helicobacter pylori (H pylori). This study aimed at determining the eradication rate using
clarithromycin 500 mg thrice daily and
omeprazole 40 mg daily for two weeks. Patients were given an endoscopy and H pylori status assessed by
antral culture (microaerobic conditions, for up to 10 days),
antral and corpus histology tests (haematoxylin and
eosin/Gimenez stains), and 13C-urea breath test (13C-UBT, European standard protocol, positive result = excess delta 13CO2 excretion > 5 per
mil). Compliance was assessed by returned
tablet counts. H pylori clearance at the end of treatment and eradication four weeks after finishing treatment were assessed by the 13C-UBT. Seventy three patients (54 men, median age 45 years) with
duodenal ulcers (n = 42) or
duodenitis/non-
ulcer dyspepsia (n = 31) all with a positive 13C-UBT (mean (SEM) excess delta-13CO2 excretion = 26.6 (4.9) per
mil) and either positive
antral histology (n = 72) or positive
antral culture (n = 35) were studied. Before treatment 2/27 (7%) isolates of H pylori were resistant to
clarithromycin and five isolates were resistant to
metronidazole. In 70/73 (96%) the 13C-UBT was negative immediately after finishing treatment. Four weeks later the 13C-UBT was negative in 57/73 (mean (SEM) excess delta 13CO2 excretion = 1.2 (0.3) per
mil, eradication rate = 78%). Forty eight (66%) patients experienced a
metallic taste while taking the
tablets. Although four (5%) patients, however, could not complete the course of treatment, in only one of these four was H pylori not eradicated. These results show that duel
therapy with
clarithromycin and
omeprazole is well tolerated. With an eradication rate of 78% it is an effective treatment for
metronidazole resistant H pylori and may be an alternative to standard triple
therapy.