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Metronidazole, Bismuth Oxide and Tetracycline Hydrochloride Fixed‑Dose Combination vs Standard First‑line Therapy for Adults with Helicobacter pylori Infection

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

The trial enrolls adults who have Helicobacter pylori infection, a bacterial condition that can lead to stomach ulcers and discomfort. The purpose is to determine whether a new fixed‑dose combination treatment is not worse than the standard first‑line therapy for eliminating the infection.

The new test medication combines three ingredients: Metronidazole, Bismuth oxide and Tetracycline hydrochloride. The standard regimen used for comparison contains a proton‑pump inhibitor (Esomeprazole) together with two antibiotics, Clarithromycin and Amoxicillin, plus metronidazole.

Participants take the assigned pills for about two weeks, after which they undergo a breath test called the Urea Breath Test that checks for the presence of the bacteria. Follow‑up visits record any side effects, how well the medication was taken, and whether the infection has been cleared.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Randomization and medication pack receipt

    After joining the study, the patient is assigned by the study system to one of two treatment groups. the assignment is concealed from the patient (single‑blind).

    The patient receives a sealed medication pack that contains all tablets needed for the treatment period. the pack includes written instructions that describe how and when each tablet should be taken.

  2. Step 2

    Baseline urea breath test

    On the first day, the patient provides a breath sample for a urea breath test (ubt). this test uses a small amount of a harmless substance called 13c‑urea to confirm the presence of helicobacter pylori infection before treatment begins.

  3. Step 3

    Start of eradication therapy (days 1–14)

    The patient begins the medication regimen immediately after the baseline ubt. the regimen depends on the assigned group:

    test arm (fixed‑dose combination): take four tablets of the combination containing metronidazole, bismuth oxide and tetracycline hydrochloride twice daily (morning and evening) with water. the total duration is 14 days.

    comparator arm (standard quadruple therapy): take the following tablets twice daily for 14 days:

    - esomeprazole 40 mg capsule (two capsules per day, total 80 mg) to reduce stomach acid,

    - clarithromycin 500 mg film‑coated tablet,

    - amoxicillin 1 g dispersible tablet,

    - metronidazole 500 mg hard capsule.

    All tablets in the comparator arm are taken with meals unless otherwise indicated in the written instructions.

  4. Step 4

    Daily medication diary and adherence monitoring

    Throughout the 14‑day treatment period, the patient records each dose taken in a provided diary. the diary is used later to assess whether at least 90 % of the prescribed units were consumed.

    The patient returns any unused tablets to the study site at the end of the treatment period for count verification.

  5. Step 5

    Post‑treatment follow‑up urea breath test (approximately day 28)

    Two weeks after completing the medication course, the patient returns for a second urea breath test. this test determines whether the helicobacter pylori infection has been cleared.

    The result of this test is the primary measure of treatment success in the study.

  6. Step 6

    Final study visit and completion

    During the final visit, the patient discusses any adverse events experienced during the trial, returns the completed diary, and receives a summary of study participation.

    No further medication is required after the follow‑up ubt.

Who can join the trial?

6 criteria

  • You must be at least 18 years old.
  • You must have an active Helicobacter pylori (H. pylori) infection that was confirmed by a gastroscopy (a camera that looks inside the stomach) and a laboratory CLO test (a test that detects the bacteria).
  • You must not have received any previous treatment or medication for H. pylori infection.
  • You must have a clear medical reason to undergo eradication therapy (treatment aimed at removing the infection).
  • You must be willing and able to take the study medication exactly as prescribed, at the correct dose and schedule, for the entire study period.
  • You must agree to sign a voluntary written informed consent form before any study procedures begin.

Who cannot join the trial?

19 criteria

  • Taking any antibiotics (drugs that kill bacteria) within the last 4 weeks.
  • Taking proton‑pump inhibitors (PPIs) or potassium‑competitive acid blockers (PCABs) (medicines that lower stomach acid) within the last 2 weeks.
  • Taking bismuth compounds (a type of medicine sometimes used for stomach problems) within the last 4 weeks.
  • Having Zollinger‑Ellison syndrome, a rare condition that makes the stomach produce too much acid.
  • Having serious problems with major organs, such as severe or unstable heart, lung, or hormone diseases.
  • Having any of the following stomach or digestive problems: bleeding in the gastrointestinal tract, iron‑deficiency anemia (low iron causing tiredness), Barrett’s esophagus (changes in the lining of the esophagus) or high‑grade dysplasia (severe abnormal cells), difficulty swallowing (dysphagia), or idiopathic thrombocytopenic purpura (ITP) (low platelet count that can cause bleeding).
  • Having Cockayne syndrome, a rare genetic disorder that affects growth and development.
  • Having low potassium (hypokalaemia) or low magnesium (hypomagnesaemia) because these can lengthen the heart’s QT interval and increase the risk of abnormal heart rhythms.
  • Having diagnosed or suspected atrophic gastritis (thinning of the stomach lining) that could interfere with the urea breath test used to detect Helicobacter pylori.
  • Any other medical condition or laboratory result during screening that the doctor believes is important enough to prevent participation.
  • History of substance or alcohol abuse within the past year.
  • Allergy (hypersensitivity) to any of the study drugs (metronidazole, bismuth, tetracycline, amoxicillin, clarithromycin, esomeprazole, 13C‑urea) or to related drug classes, or a severe immediate allergic reaction (such as anaphylaxis) to beta‑lactam antibiotics (e.g., penicillins, cephalosporins).
  • History of a prolonged QT interval (congenital or acquired) or dangerous heart rhythm problems, including a type called torsades de pointes.
  • Being pregnant or breastfeeding (lactation).
  • Regular use of non‑steroidal anti‑inflammatory drugs (NSAIDs) or systemic steroids (anti‑inflammatory medicines) within the past 4 weeks.
  • Use of blood thinners (anticoagulants) or antiplatelet agents (medicines that prevent clotting) within the past 4 weeks, except low‑dose aspirin (100 mg per day or less).
  • Taking any other prohibited medication that could have serious interactions with the study treatments.
  • Having had previous stomach or upper gastrointestinal surgery, such as gastric surgery or gastrectomy.
  • Having severe additional illnesses, such as advanced kidney, liver, or heart failure, or having cancer (malignancy).
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Investigated drugs

  • Esomeprazole

    is a medication that reduces the amount of acid made by the stomach. In this study it is given to help protect the stomach lining and create a better environment for the antibiotics to work against the infection.

  • Clarithromycin

    is an antibiotic that kills bacteria. It is part of the standard treatment regimen used in the trial to try to clear the Helicobacter pylori infection.

  • Amoxicillin

    is another antibiotic that works by stopping bacteria from building their cell walls. It is combined with other medicines in the standard therapy to increase the chance of eradicating the infection.

  • Metronidazole

    is an antibiotic that is effective against certain types of bacteria and other microorganisms. In the trial it is used as part of the standard four‑drug regimen and also appears in the experimental combination.

  • Metronidazole, Bismuth oxide, and Tetracycline combination

    is the test product being evaluated. It combines three agents in one tablet: metronidazole (an antibiotic), bismuth oxide (a compound that coats the stomach lining and has mild antibacterial effects), and tetracycline (an antibiotic that stops bacterial growth). The study tests whether this fixed‑dose combination works as well as the standard therapy for removing Helicobacter pylori.

  • 13C‑urea breath test

    is a diagnostic tool used to detect Helicobacter pylori infection. Patients swallow a small amount of a special substance (13C‑urea), and the breath is analyzed to see if the bacteria are present. This test helps confirm that participants have the infection before treatment begins.

What is already known about the treatment

  • Esomeprazole

    This medication comes as a gastro‑resistant hard capsule taken by mouth. It is a widely approved proton‑pump inhibitor that reduces stomach acid by blocking the acid‑producing pump in the lining of the stomach. It is mainly used to treat acid‑related conditions such as heartburn and ulcers, and it is also given together with antibiotics to help treat Helicobacter pylori infection. It is a prescription drug found in many standard treatment guidelines.

  • Clarithromycin

    Clarithromycin is supplied as a film‑coated tablet for oral use. It is a macrolide antibiotic that stops bacteria from making proteins, which prevents them from growing. It is commonly prescribed for respiratory infections and is part of the standard regimen for eradicating Helicobacter pylori. The drug is approved and listed in major medical references.

  • Amoxicillin

    Amoxicillin is provided as a dispersible tablet that is taken by mouth and dissolved in water. It belongs to the penicillin class of antibiotics and works by weakening the bacterial cell wall, causing the bacteria to die. It is used for many infections, including as a component of first‑line therapy for Helicobacter pylori. It is an established, widely prescribed medicine.

  • 13C‑Urea

    This product is a powder that is mixed with water to make an oral solution for a breath test. It is a diagnostic agent in which the urea molecule is labeled with carbon‑13; Helicobacter pylori in the stomach breaks it down, releasing labeled carbon dioxide that can be measured. The test helps doctors confirm the presence of the infection without using a drug that treats disease. It is approved for diagnostic use in many countries.

  • Metronidazole

    Metronidazole is available as a hard capsule taken orally. It is an antibiotic and antiprotozoal agent that damages bacterial DNA, leading to cell death, especially in anaerobic (oxygen‑low) bacteria. It is used to treat infections such as bacterial vaginosis, certain gastrointestinal infections, and as part of Helicobacter pylori eradication regimens. It is an approved prescription medication.

  • Tetracycline hydrochloride

    Tetracycline hydrochloride comes as an oral tablet. It is a broad‑spectrum antibiotic that blocks the ability of bacteria to make proteins, stopping their growth. It is used for a variety of infections, including as a component of quadruple therapy for Helicobacter pylori. The drug is listed in standard pharmacopeias and requires a prescription.

Investigated diseases

Helicobacter pylori infection - Helicobacter pylori infection is a bacterial infection of the stomach lining caused by the spiral‑shaped bacterium Helicobacter pylori. The bacteria settle in the protective mucus of the stomach, leading to irritation and inflammation. As the infection persists, the stomach lining can become thicker and develop small sores. Continued inflammation may cause changes in the lining that result in ulcer formation.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2026-525291-26-00Protocol codeHELICA/VEREstimated enrolment420 patientsSponsorVerisfield Single Member S.A.

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