Clarithromycin–Amoxycillin-Containing Triple Therapy: A Valid Empirical First-Line Treatment for Helicobacter pylori Eradication in Hong Kong? Ivan F.N. Hung,* Pierre Chan,* Sally Leung, † Fion S.Y. Chan, ‡ Axel Hsu,* David But,* Wai Kay Seto,* Siu Yin Wong,* Chi Kuen Chan,* Qing Gu,* Teresa S.M. Tong,* Ting Kin Cheung,* Kent Man Chu ‡ and Benjamin C.Y. Wong* * Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, † Department of Microbiology, University of Hong Kong, Queen Mary Hospital, Hong Kong, ‡ Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong Since the discovery of Helicobacter pylori by Warren and Marshall [1] in 1982, much has been learned about this gram-negative microaerophilic bacterium and its associ- ated pathology. It was soon recognized to be the culprit for causing recurrent peptic ulcers and gastric malignancies including mucosa-associated lymphoid tissue (MALT) lymphoma and gastric adenocarcinoma [2]. Different combinations of proton-pump inhibitors (PPI) and anti-H.pylori have evolved to eradicate this pathogen. Despite this, the combination of PPI, Keywords Helicobacter pylori, empirical first-line eradication, levofloxacin, clarithromycin, Hong Kong. Reprint requests to: Benjamin C.Y. Wong, Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong. E-mail: bcywong@hku.hk Abstract Background: Recent studies have suggested the eradication rate for Helico- bacter pylori infection with standard amoxycillin–clarithromycin-containing triple therapy as first-line treatment have fallen below 80%. Levofloxacin- containing triple therapy was proposed as an alternative. The aim of this study is to compare the efficacy and tolerability of the standard 7-day clari- thromycin-containing triple therapy against the 7-day levofloxacin-contain- ing triple therapy, and to assess whether the classical triple therapy is still valid as empirical first-line treatment for H. pylori infection in Hong Kong. Methods: Three hundred consecutive H. pylori-positive patients were ran- domized to receive either 1 week of EAL (esomeprazole 20 mg b.d., amoxy- cillin 1 g b.d., and levofloxacin 500 mg daily) or EAC (esomeprazole 20 mg b.d., amoxycillin 1 g b.d., and clarithromycin 500 mg b.d.). H. pylori status was rechecked by 13 C-urea breath test 6 weeks after treatment. Patients who failed either of the first-line eradication therapy were invited to undergo H. pylori susceptibility testing. Results: H. pylori eradication was achieved in 128 of 150 (85.3%) patients in EAL and 139 of 150 (92.7%) patients in EAC groups, respectively (p = .043), for both intention-to-treat and per-protocol analysis. More patients in the clarithromycin- than the levofloxacin-containing therapy group developed side effects from the medication (21.3% vs 13.3%, p = .060). Nine patients (six from the EAL group and three from the EAC group) who failed their corresponding eradication therapy returned for susceptibility testing. All nine isolates were highly resistant to levofloxacin (minimum inhibitory concentration or MIC > 32 lg ⁄ mL), whereas only two of the six isolates from the EAL group were resistant to clarithromycin (MIC > 0.5 lg ⁄ mL). Conclusions: The standard 7-day clarithromycin-containing triple therapy is still valid as the most effective empirical first-line eradication therapy for H. pylori infection in Hong Kong, as prevalence of primary resistance of H. pylori to amoxycillin and clarithromycin remains low. Patients who failed their empirical first-line eradication therapy should undergo H. pylori suscep- tibility testing to guide further treatment. Helicobacter ISSN 1523-5378 ª 2009 Blackwell Publishing Ltd, Helicobacter 14: 505–511 505