Helicobacter pylori eradication treatment in Irish primary care: a retrospective cross-sectional analysis of prescribing trends from 2012–2022

Abstract Introduction Helicobacter pylori (H. pylori), a bacterium associated with chronic gastritis, peptic ulcer disease, and gastric malignancies, infects approximately 44% of the world’s population.1 Primary clarithromycin resistance, exceeding 25% in the Republic of Ireland, drives frequent failure of clarithromycin-based regimens. Currently, the national consensus guidelines for H. pylori management recommend 14-day bismuth quadruple therapy (BQT) as first-line unless clarithromycin susceptibility is confirmed.2 However, bismuth remains unauthorised by the Irish Health Products Regulatory Authority, limiting BQT availability. Aim The aim of this study was to explore the trends of prescribing H. pylori eradication treatment in Ireland and the impact of the first-line regimen choice on treatment failure over the study period. Methods A repeated cross-sectional analysis of the national pharmacy claims database, covering individuals eligible for the General Medical Services (GMS) scheme (30% of the Irish population), was conducted for the period 2012–2022. Prescribing rates per 100 000 GMS population were computed for ten H. pylori eradication regimens, corresponding to various antimicrobial and proton-pump inhibitor (PPI) combinations. Associations between treatment prescribing and sex (male/female) and age groups (≤45/45 years) were assessed using χ2-tests. The p-value 0.05 was considered significant. An eradication treatment was considered failed if followed by a subsequent prescription of any H. pylori regimen. Failure rate (%) was calculated as the number of failed prescriptions divided by the total prescriptions for each regimen. Results Between 2012 and 2022, a total of 113 555 H. pylori eradication treatments were prescribed to 90 124 patients. Clarithromycin-amoxicillin triple therapy was the most prescribed regimen (median = 464.5/100000 GMS), while BQT was rarely prescribed (median = 0.8/100000 GMS). Treatment duration was known for 85.9% of prescribed treatments, ranging from 1–24 days (mean = 9.3, SD ± 3.5). While 14-day prescriptions increased, 7-day prescriptions declined over time. Women (χ2 = 273, p 0.001) and patients aged ≥45 years (χ2 = 8569, p 0.001) were more likely to receive treatment. Overall, 16.8% of patients failed first treatment, more commonly women (χ2 = 50, p 0.001) and patients aged 45 years (χ2 = 172, p 0.001). Of these, 66.4% received the same regimen at least twice, and more than half (52.7%) were re-treated within six months. Clarithromycin-metronidazole and amoxicillin-clarithromycin triple therapies exhibited the highest failure rates—15.2% and 13.7%, respectively. The failure rate of BQT was 8.4%. Conclusion Clarithromycin-based eradication regimens remained predominant in Irish primary care over the study period, despite high clarithromycin resistance and poor treatment outcomes. Although associated with lower failure rates, BQT was rarely prescribed. The increase in 14-day treatment duration is consistent with national guidelines. However, frequent re-prescription of failing regimens indicates a gap between guideline recommendations and prescribing practice. Facilitating access to BQT, addressing prescriber education, and introducing routine susceptibility testing could contribute to improved H. pylori eradication success in Ireland. A key strength of this study is the large volume of national prescribing data collected over an 11-year period. Its main limitation is that prescriptions were used as a proxy for H. pylori diagnosis, without the ability to confirm infection status or clinical outcomes.