Tetracycline, metronidazole and amoxicillin-metronidazole combinations in proton pump inhibitor-based triple therapies are equally effective as alternative therapies against Helicobacter pylori infection

Background: A proton pump inhibitor (PPI)-based triple therapy with clarithromycin (CAM) and amoxicillin (AMPC) is now a standard regimen for Helicobacter pylori (HP) eradication in Japan. However, the CAM-resistant rate has increased recently and alternative therapies are sorely needed. Therefore the aim of the present study was to evaluate the effectiveness and safety of the PPI-tetracycline (TC)-metronidazole (MNZ) regimen (the PTM regimen) as an alternative therapy in comparison with the PPI-AMPC-MNZ (PAM) regimen. Methods: Sixty-four HP-positive patients visiting the HP-eradication clinic in Tokai University Hospital from July 1998 to March 2003 were treated with either PTM or PAM as alternative therapies. The HP eradication was assessed by urea breath test (UBT), HP stool antigen test, or HP culture method more than 2 months after completion of the treatments. The drug resistances against CAM, AMPC, TC, and MNZ were assessed by the agar dilution method. Results: Fifty-six patients (26 PTM and 30 PAM) completed medication and evaluation of the eradication. The eradication rates of PTM were 82.8% (24/29) and 92.3% (24/26), while those of PAM were 74.3% (26/35) and 89.7% (26/29) by intention-to-treat and per-protocol analysis, respectively. The differences between the regimens were not statistically significant. There were no severe adverse effects observed in either of the regimens. The drug-resistance analyses showed 15 CAM- and one MNZ-resistant cases but no TC or AMPC resistance in the available 25 samples. Conclusion: The PTM and PAM regimens were equally effective and safe as alternative HP eradication therapies. And PTM would be particularly useful in penicillin allergy cases.