Impact of insufficient doses of medications on Helicobacter pylori eradication: a retrospective observational study

Background and aims The doses of medications may influence the success of Helicobacter pylori (H. pylori) eradication. This real-world observational study aimed to explore the impact of insufficient doses of medications prescribed for the bismuth-containing quadruple therapy (BQT) regimen on successful H. pylori eradication. Methods We retrospectively screened the patients who were diagnosed with H. pylori infection and received BQT regimens for H. pylori eradication at our department between January 2017 and July 2020. The rate of successful H. pylori eradication was compared according to the doses of medications prescribed. Standard doses were defined according to the clinical guidelines. Results Overall, 1054 patients were included. The rate of successful H. pylori eradication was 78.2% (824/1054). Among them, proton pump inhibitors (PPIs) and antibiotics were prescribed at insufficient doses in 37.0% (390/1054) and 6.7% (71/1054) of patients, respectively. Furthermore, pantoprazole (98.7% [385/390]) was the most common type of PPIs prescribed at insufficient doses, and nitroimidazoles (85.9% [61/71]) were the most common type of antibiotics prescribed at insufficient doses. Among the patients receiving colloidal bismuth pectin (CBP) (200 mg tid) and standard-dose antibiotics, the rate of successful H. pylori eradication was lower in insufficient-dose PPIs group than standard-dose PPIs group (78.1% [271/347] versus 82.6% [438/530], P = 0.095). Among the patients receiving CBP (200 mg tid) and standard-dose PPIs, the rate of successful H. pylori eradication was significantly lower in insufficient-dose antibiotics group than standard-dose antibiotics group (37.8% [14/37] versus 82.6% [438/530], P < 0.0001). Among the patients receiving CBP 200 mg tid, the rate of successful H. pylori eradication was significantly lower in patients receiving both PPIs and antibiotics at insufficient doses than those at standard doses (46.4% [13/28] versus 82.6% [438/530], P < 0.0001). Conclusion Among the BQT regimens, PPIs and/or antibiotics, especially pantoprazole and metronidazole, are often prescribed at insufficient doses, compromising the success of H. pylori eradication.