Efficacy of clarithromycin-based triple therapy for treating Helicobacter pylori in Thai non-ulcer dyspeptic patients with clarithromycin-resistant strains.

BACKGROUND Antibiotic resistance of H. pylori is problematic because it reduces the efficacy of eradication therapy. The objective of the present study was to assess the eradication rates of triple therapy against clarithromycin-sensitive and clarithromycin-resistant strains of H. pylori in Thai non-ulcer dyspeptic patients. MATERIAL AND METHOD Patients who underwent upper gastrointestinal endoscopy at King Chulalongkorn Memorial Hospital between September 2002 and December 2003 were included. The patients who had positive urease test and culture were enrolled for antimicrobial resistance. Isolates were considered resistant when the MIC was more than 1 mcg/ml for clarithromycin. The patients received a combination of pantoprazole 40 mg BID, clarithromycin MR 1 gm OD, and amoxicillin 1 gm BID, for 7 days. Urea [14C] breath test was performed for evaluation of H. pylori eradication at least 1 month after treatment. RESULTS Of the 470 patients, H. pylori were identified by positive rapid urease test in 282 patients (69.0%). Of these, cultures for H. pylori were achieved in 113 patients (54.6%) and E-tests for clarithromycin were successfully placed in 69 isolations. There were 29 males and 40 females, mean age was 38.7 +/- 13.3 years. Primary H. pylori resistance to clarithromycin was observed in 16 of 69 patients (23.2%). The eradication rates were 90.6% (48/53) and 56.3% (9/16) in patients with clarithromycin sensitive and clarithromycin resistant H. pylori strains, respectively (p = 0.002). CONCLUSION The authors reported a high rate of clarithromycin resistant H.pylori isolates in Thailand. Pretreatment resistance to clarithromycin has a significant impact on treatment failure with clarithromycin-based regimen.