Clarithromycin Resistance Impedes H. pylori Eradication

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http://www.medscape.com/viewarticle/503740

Clarithromycin Resistance Impedes H. pylori Eradication

Reuters Health Information 2005.

NEW YORK (Reuters Health) Apr 22 - Resistance to clarithromycin has a major impact on eradication of Helicobacter pylori infection in adults treated with triple-drug therapy that includes clarithromycin, Korean researchers report in the April issue of Antimicrobial Agents and Chemotherapy.

Clarithromycin-resistant H. pylori isolates are becoming increasingly common, the researchers note, although it is not clear what impact they have on the success of eradication therapy in patients with peptic ulcers.

Dr. Jong Hwa Lee of Dankook University College of Medicine, Cheonan and colleagues analyzed the outcome of 114 dyspeptic patents with confirmed H. pylori infection who were treated twice daily with omeprazole 20 mg, together with twice-daily amoxicillin 1g and twice-daily clarithromycin 500 mg for 10 days.

Clarithromycin resistance was documented in 20.2% of 114 isolates cultured from biopsy specimens taken at endoscopy and was largely caused by an A2142G mutation in the 23S rRNA gene of H. pylori.

H. pylori was successfully eradicated in all patients with clarithromycin-sensitive isolates but in none of the patients with clarithromycin-resistant isolates.

Given that the presence of clarithromycin-resistant isolates was "100% predictive of treatment failure," the researchers conclude that " it would be useful to conduct H. pylori antimicrobial susceptibility testing of the first gastric biopsy culture before choosing the first three drugs for therapy of infected patients."

Antimicrob Agents Chemother 2005;49:1600-1603.