Helicobacter pylori

RBC triple therapy in metronidazole- and clarithromycin-resistant Hpylori: Antibiotic resistance, particularly to metronidazole, can reduce the efficacy of Hpylori treatment regimens containing metronidazole. However, dual therapy with RBC and clarithromycin may be effective, with reported eradication in 11 of11 metronidazole-resistant H pylori strains. In this study, metronidazole resistance was defined as an MIC greater than 8 pg/mL by the E-test. In the same study, triple therapy with RBC, clarithromycin and metronidazole overcame metronidazole resistance in nine of 10 strains. Similar results were reported by Bardhan et al, who reported that triple therapy with RBC, clarithromycin 500 mg bid and metronidazole 400 mg bid for seven days successfully eradicated baseline metronidazole-resistant H pylori strains in nine of 10 patients.

In another clinical trial, the effects of two different RBC triple therapies on resistant H pylori strains were evaluated. Patients were treated for one week with RBC 400 mg bid, metronidazole 500 mg bid and clarithromycin 500 mg bid (RMC) or RBC 400 mg bid, metronidazole 500 mg bid and amoxicillin 1 g bid (RMA). In this study, metronidazole resistance was defined as an MIC greater than 8 g/mL by the E-test, and clarithromycin resistance was defined as an MIC greater than 2 g/mL. With RMC, the overall eradication rate was 96% (107 of 111 patients) and was unaffected by prestudy metronidazole resistance (95% eradication in 20 patients). H pylori was also eradicated in three patients with baseline clarithromycin-resistant strains and in a patient infected by a strain resistant to both metronidazole and clarithromycin. For RMA, the overall eradication rate was 79% – 87% in metronidazole-susceptible strains but only 22% in resistant strains. This suggests that RMC triple therapy may overcome the in vitro metronidazole or clarithromycin resistance to eradicate H pylori. However, substituting clarithromycin with amoxicillin was not successful. You will always come across cialis professional offered by a reliable pharmacy.

With RBC, clarithromycin and amoxicillin triple therapy, efficacy was not reduced by baseline metronidazole resistance. Further studies will be important to substantiate these observations and to help identify the role of RBC-based treatments in patients who have failed initial therapy.