Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized Controlled Trial of Triple Therapy Versus Sequential Therapy Versus Concomitant Therapy as First Line Treatment for Helicobacter Pylori Infection
Brief Summary: Triple therapy (TT) comprising proton pump inhibitor (PPI), amoxicillin 1g and clarithromycin 500mg twice daily has long been considered one of the standard treatment for H. pylori infection as initial studies demonstrated success rates of \> 90% on per protocol analysis (PP) and \> 80% on intention to treat (ITT) analysis. However increasing bacterial resistance, especially to clarithromycin, has been reported and there are concerns that the efficacy of TT has decreased. Sequential therapy (ST) is an alternative first line therapy that consists of 5 days of treatment with a PPI and amoxicillin followed by 5-day treatment with the PPI and clarithromycin and metronidazole. The rationale for this approach is that amoxicillin may weaken the bacterial cell wall in the initial phase of treatment, and prevent the development of drug efflux channels that inhibit clarithromycin from binding to ribosomes and thus help to improve the efficacy of clarithromycin in the second phase of treatment. A recent meta-analysis based on mainly European studies showed that the success rate of ST compared to TT was 92.8 - 96% vs. 76.2 - 78.8%. Concomitant therapy (CT) is another alternative first line treatment that consists of 10 days of PPI, amoxicillin, clarithromycin and metronidazole. The rationale for using CT as a first line treatment option is to address the possibility of clarithromycin resistance which is increasingly encountered in clinical practice. Currently there are no randomized controlled studies that compared TT with ST in Singapore, although both regimens are being used in routine clinical practice. The hypothesis is that ST is superior to TT as first line treatment for H. pylori infection.

The study aim to compare 10-day TT versus 10-day ST versus 10-day CT as first line treatment for H. pylori infection in Singapore.


Options:
A: Inclusion Criteria:

* Consecutive H. pylori-infected outpatients, at least 20 years of age, with endoscopically proven peptic ulcer diseases or gastritis

Exclusion Criteria:

* previous H. pylori-eradication therapy
* ingestion of antibiotics, bismuth, or proton pump inhibitors within the prior 4 weeks
* patients with allergic history to the medications used
* patients with previous gastric surgery
* the coexistence of serious concomitant illness (for example, decompensated liver cirrhosis, uremia)
* pregnant women
B: Inclusion Criteria:

1. Patients are aged greater than 20 years who have H. pylori infection without prior eradication therapy and are willing to receive the sequential therapy will be eligible for enrollment.

Exclusion Criteria:

1. children and teenagers aged less than 20 years,
2. history of gastrectomy,
3. gastric malignancy, including adenocarcinoma and lymphoma,
4. previous allergic reaction to antibiotics (amoxicillin, clarithromycin, levofloxacin, metronidazole) and prompt pump inhibitors (lansoprazole),
5. contraindication to treatment drugs,
6. pregnant or lactating women,
7. severe concurrent disease,
8. Patients who cannot give informed consent by himself or herself.
C: Inclusion Criteria:

* Helicobacter pylori infected patients \> 18 years

Exclusion Criteria:

* previous H. pylori eradication treatment;
* Use of proton pump inhibitors, H2-receptor antagonists, bismuth preparations and antibiotics in the previous 4 weeks;
* Concomitant anticoagulant or ketoconazole use, due to the potential of interaction with the study medications;
* Zollinger-Ellison syndrome;
* Previous surgery of the esophagus and/or upper gastrointestinal tract (with the exception of appendectomy, polypectomy and cholecystectomy);
* Severe or unstable cardiovascular, pulmonary, or endocrine disease; clinically significant renal or hepatic disease or dysfunction; hematological disorder; any other clinically significant medical condition that could increase the risk to the study participants; malignant disease of any kind during the previous 5 years except for successfully treated skin (basal or squamous cell) cancer or Barrett esophagus with high grade dysplasia;
* Drug or medication abuse within the past year;
* Severe psychiatric or neurological disorders;
* Pregnant or nursing women sexually active women of child bearing potential who were not willing to practice medically acceptable contraception (oral contraceptives; inject able/implantable or mechanical devices as well as vasectomy of the sexual partner) for the entire duration of the study.
D: Inclusion Criteria:

* consecutive patients newly diagnosed to have H. pylori infection.

Exclusion Criteria:

* known allergy to any of the treatment drugs
* inability to undergo routine test to confirm success of H. pylori eradication
* previous H. pylori therapy.

Answer: D