Update on Clarithromycin Resistance in <i>Helicobacter pylori</i> in Hong Kong and Its Effect on Clarithromycin-Based Triple Therapy

Abstract

Aim: To determine the antibiotic susceptibility of Helicobacter pylori and evaluate the efficacy of a clarithromycin-based triple therapy in relation to antibiotic resistance. Methods: Consecutive patients referred for upper endoscopy due to dyspeptic symptoms were recruited. Gastric biopsies were obtained for the CLO test, histology and culture. Antibiotic susceptibility was assessed by the E-test. Patients with H. pylori infection received rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily for 7 days. Results: Of 234 patients recruited, 124 were H. pylori-positive and culture was successful in 102 patients. The updated prevalences of resistance to clarithromycin, amoxicillin and metronidazole were 7.8, 0 and 39.2%, respectively. A total of 86 patients received 1-week triple therapy with rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily, and 81 patients attended the follow-up test. Eradication rates by per-protocol and intention-to-treat analysis were 92.6 and 87.2%, respectively. The eradication rate by per protocol was significantly higher in patients with clarithromycin-susceptible strains than in those with clarithromycin-resistant strains (98.6 vs. 28.6%, p < 0.001). Conclusion: Clarithromycin resistance reduces the clinical efficacy of clarithromycin-based triple therapy. However, due to the low prevalence of clarithromycin resistance, clarithromycin-based therapy is still the first choice for clinical use.

Long-term proton pump inhibitors and risk of gastric cancer development after treatment for Helicobacter pylori: a population-based study

“…Second, although patients who failed triple therapy were identified by the repeated prescription of clarithromycin-based triple therapy or prescription of second-line and third-line therapies, it remains possible that a small proportion of patients who failed H. pylori eradication therapy might be missed. In this study, about 13% of patients received a second course of eradication therapy, which is compatible with the observed success rate of clarithromycin-based triple therapy in our population with relatively low prevalence of clarithromycin resistance during the study period 23. In addition, we have validated the negative H. pylori status of all 12 gastric cancer cases from our hospital.…”

“…The start date of the prescriptions should be the same, with an overlapping duration of 7–14 days. Clarithromycin-based triple therapy was the first-line therapy for H. pylori in Hong Kong during the study period due to the low clarithromycin resistance rate (8%)23 and overall high eradication rate (>90%) 24. To remove the confounding effects of symptoms from gastric cancer leading to the use of PPIs or histamine 2-receptor antagonist (H2RA) (ie, protopathic bias), prescriptions of these agents started within 6 months prior to the gastric cancer diagnosis were excluded 25 26…”

Clarithromycin–Amoxycillin‐Containing Triple Therapy: A Valid Empirical First‐Line Treatment for Helicobacter pylori Eradication in Hong Kong?

“…As a result, quinolonecontaining triple therapy has been proposed as a replacement for the standard clarithromycin-containing triple therapy, achieving an ITT eradication rate of 84-87% [8,9]. Reasons for this well-maintained high eradication rate is likely to be multifactorial, including low prevalence of amoxycillin-and clarithromycinresistant H. pylori strains [15], better patients' compliance, and higher frequency of CYP2C19 poor metabolizers in Asian population than Caucasians [16,17]. Reasons for this well-maintained high eradication rate is likely to be multifactorial, including low prevalence of amoxycillin-and clarithromycinresistant H. pylori strains [15], better patients' compliance, and higher frequency of CYP2C19 poor metabolizers in Asian population than Caucasians [16,17].…”

“…The isolate would be considered to be resistant when MICs were greater than 1 lg ⁄ mL for levofloxacin and amoxycillin, and 0.5 lg ⁄ mL for clarithromycin [10,14,15]. Two antral biopsies were taken during the procedure and sent for histologic examination, and H. pylori culture.…”

Prevalence of antimicrobial resistance in Helicobacter pylori isolates in Taiwan in relation to consumption of antimicrobial agents

“…The standard recommended method to treat infected patients with severe symptoms was the combination of a proton pump inhibitor and two antibiotics, mainly clarithromycin with either amoxicillin or metronidazole [3]. An eradication rate >90% was found in a number of reports based on this combination therapy [4]. However, widespread use of antibiotics has led to a relatively high failure rate (20-40%) in the past years [5].…”