NCT01572597.

Trial name or title	Increased second‐line eradication rate of helicobacter pylori by adding N‐acetylcystein or metronidazole to the conventional triple therapy
Methods	Allocation: randomised. Intervention model: parallel assignment. Masking: open label. Primary purpose: treatment.
Participants	Participant (20 to 80 years old) after treatment for H pylori eradication Still clinically with evidence of gastric H pylori infection
Interventions	Experimental: acetylcysteine 10‐day triple therapy plus N‐acetylcysteine to remove the biofilm. Active comparator: metronidazole 10‐day triple therapy plus metronidazole (concomitant therapy) as the active comparator.
Outcomes	Primary outcome measures: re‐eradication rate (time frame: 4 weeks after complete use of drug for treatment). A negative post‐treatment C13‐urea breath test result at more than 4 weeks after complete use of drug for treatment. Secondary outcome measures: influence of participant's CYP2C19 genotype on re‐eradication rate (time frame: 4 weeks after complete use of drug for treatment). Influence of participant's CYP2C19 genotype (EM, IM or PM) on re‐eradication rate of H pylori
Starting date	June 2011
Contact information	Ming‐Cheh CHEN, M.D. MingCheh_chen@tzuchi.com.tw
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