Clarithromycin resistance, but not CYP2C-19 polymorphism, has a major impact on treatment success in a 7-day treatment regimen for cure of H. pylori infection: A logistic regression analysis

Second-line treatment for Helicobacter pylori infection in Japan: proton pump inhibitor-based amoxicillin and metronidazole regimen

“…15 It is well known that clarithromycin resistance has a significant impact on the treatment success of the PPI/AC regimen. [16][17][18] Although the primary resistance rate against clarithromycin was only 6.0% in our patient population (unpublished data), H. pylori has been shown to easily acquire secondary resistance to clarithromycin. Therefore, acquired secondary resistance would affect the efficacy of secondline therapy, resulting in an insufficient cure rate with repeated PPI/AC treatment.…”

Efficacy of metronidazole for the treatment of clarithromycin-resistant Helicobacter pylori infection in a Japanese population

“…2 The proportion of the CLA-resistant strain is increasing, and many strains acquire resistance to this antibiotic, particularly after the failure of first-line therapy. On the other hand, resistance to AMOX is very rare, and acquisition of resistance to AMOX also rarely occurs even after the failure of first-line therapy.…”

Comparison of efficacies of dual therapy and triple therapy using rabeprazole in second‐line eradication of Helicobacter pylori in Japan

“…CAM sensitivity is reported to be the most important factor in determining the success or failure of PPI/AC regimens. 18 The proportion of CAM-resistant strains is reported to be high following eradication failure with PPI/AC therapy, at 66% according to Murakami et al 19 and 70% according to Tankovic et al 20 PPI/AC eradication rates for patients with CAMresistant strains are reported to be as low as 0-20%, 19,21 indicating the need for new eradication regimens. With regard to RPZ, a feature of this compound is that its action is much less influenced than other PPIs by different genotypes of CYP2C19, an isoenzyme of cytochrome P450 involved in the intrahepatic metabolism of PPIs.…”