Bismuth Quadruple Therapy Versus Modified Bismuth Therapy for Helicobacter Pylori

Study Design: Open label randomized controlled trial (RCT). Period of study:From September 2023 to September 2025 Participants: Among patients attending Gastroenterology clinic in Tropical medicine and infectious diseases department-Tanta university;200 patients with a confirmed diagnosis of helicobacter pylori infection were enrolled and allocated randomly in 2 equal parallel treatment arms.

Sample Size Calculation:

The sample size was calculated using a free online clinical trial calculator (ClinCalc.com) based on effect sizes from previous studies. A recent study in KSA reported an eradication rate of 78.3% for bismuth-based quadruple therapy \[1\]. Conversely, other studies have reported eradication rates of 88-94% \[2\] and 91.5-97.3% \[3\] for bismuth-based triple therapy. At a 95% confidence interval (α-error = 0.05) and 80% statistical power (β-error = 0.2), the minimum required sample size was 146 patients, allocated equally (73 per arm) \[4\]. To account for an anticipated attrition rate of approximately 30% a total of 200 patients (100 per group) were recruited.

Randomization and Allocation:

To ensure unbiased group assignment and concealment of the allocation sequence, a computer-generated randomization scheme was implemented. Block randomization was performed using a block size of 4, with computer-generated random permutations within each block. To minimize the risk of predicting the allocation sequence, the block size was randomly varied using blocks of 4 and 6 and was not disclosed to the treating investigator. Each enrolled patient was assigned a unique numerical identifier. The complete list of patient identifiers was then sorted in ascending order according to the generated random values. Based on this sorted sequence, the first 100 patients were allocated to Group I (Bismuth add on triple therapy), while the remaining 100 patients were assigned to Group II (Bismuth quadruple therapy). To maintain allocation concealment, the randomization sequence was generated by an independent investigator who was not involved in patient enrollment or outcome assessment. Group assignments were placed in sequentially numbered, opaque, sealed envelopes, which were opened just before starting treatment and after the enrolling physician confirmed patient eligibility and obtained written his/her informed consent.

All patients in the study will be subjected to the following:

Full history taking. Complete clinical examination. Laboratory Investigations including: complete blood picture, liver function tests and renal function tests.

Abdominal ultrasound. Confirm ation of H.pylori infection with either: quantification of H. pylori antigen in stool by ELISA, r upper gastrointestinal endoscopic biopsy and histopathological examination.

• Bismuth added on triple therapy (Drug), also known as modified bismuth quadruple therapy: A 14-day oral regimen comprising Bismuth subcitrate (240 mg twice daily), Clarithromycin (500 mg twice daily), Amoxicillin (1 g twice daily), and the proton pump inhibitor (PPI) Esomeprazole (40 mg twice daily).
• Quadruple therapy (Drug), also known as BQT: 14-day oral regimen comprising Bismuth subcitrate (240 mg twice daily), Doxycycline (100 mg twice daily), Metronidazole (500 mg three times daily), and Esomeprazole (40 mg twice daily).

Primary outcomes

• cure rate [4 weeks after the end of therapy]: cure rate in the experimental arm compared with cure rate in the comparator arm

Secondary outcomes

• adverse events [throughout the14 days of therapy]: adverse events of the two regimens in the two arms

Sex: All, ages: 18 Years to 70 Years

Inclusion Criteria:

* Patients aged ≥ 18 years.
* Confirmed diagnosis of H. pylori infection.

Exclusion Criteria:

* Pregnant or lactating women.
* Prior treatment for H. pylori infection.
* History of antibiotic or PPI use within the month preceding enrollment.
* History of hypersensitivity or allergic reaction to any of the study drugs.
* Presence of any contraindication to the study medications.
* Advanced chronic liver disease or renal disease.

• 1)Awuku YA, Simpong DL, Alhassan IK, Tuoyire DA, et al (2017): Prevalence of Helicobacter pylori infection among children living in a rural setting in subSaharan Africa. BMC Public Health.17:360 2) Alhammad M.A.a, El-Kady H.b, Hamed Y.c. (2019): Clarithromycin resistance and genetic pattern of Helicobacter pylori in a group of patients with peptic ulcer disease in Alexandria, Egypt. International Journal of scientific and technology research. 8, Issue 3,149-159 3) Alsohaibani F, Alquaiz M, Alkahtani K, et al (2020): Efficacy of a bismuth-based quadruple therapy regimen for Helicobacter pylori eradication in Saudi Arabia.Saudi Journal of Gastroenterology. 26-2 4) Chey W.D, Leontiadis G.I, Howden C.W, et al (2017): ACG Clinical Guideline: Treatment of Helicobacter pylori Infection. Am J Gastroenterol .112:212-238 5) Fagoonee, S and Pellicano, R. (2019): Helicobacter pylori: Molecular basis for colonization and survival in gastric environment and resistance to antibiotics. A short review. Infect. Dis. 51, 399-408 6)Georgopoulos.s and Papastergiou.v (2021):An update on current and advancing pharmacotherapy options for the treatment of H. pylori infection Expert Opinion on Pharmacotherapy .Volume 22- Issue 6. 7) Ghaith.D, Elzahry.M, Mostafa.G, et al (2016): Mutations affecting domain V of the 23S rRNA gene in Helicobacter pylori from Cairo, Egypt. J Chemother. 28(5):367-370 8) Isaeva, G.S and Fagoonee, S (2018): Biological properties and pathogenicity factors of Helicobacter pylori. Minerva Gastroenterol. Dietol. 64, 255-266 9).KaneS.P(2019):SampleSizeCalculatorClinCalc:https://clincalc.com/stats/samplesize.aspx. Updated July 24, 2019. Accessed July 16, 2023. 10) Liao J, Zheng Q, Liang X, et al (2013): Effect of fluoroquinolone resistance on 14-day levofloxacin triple and triple plus bismuth quadruple therapy. Helicobacter.18:373-377. 11) McNicholl A.G, Bordin D.s, Lucendo.A(2020): Combination of Bismuth and Standard Triple Therapy Eradicates Helicobacter pylori Infec