H. pylori eradication therapy: impact of gastric mucosa atrophy on transport of amoxicillin to H. pylori colonization area

AIM: The aim was to assess systemic transport of amoxicillin, the most common antibiotic in H. pylori eradication regimens to the gastric in atrophic gastritis. MATERIALS AND METHODS: Systemic transport of amoxicillin to the gastric lumen of rats was evaluated in washes from the gastric mucosa in the model of atrophic gastritis after intravenous drug infusion. Transport of amoxicillin from bloodstream to the gastric lumen was also assessed in patients with atrophic and non-atrophic gastritis in aspirated via nasogastric probe gastric juice after oral drug administration. Amoxicillin concentration was measured in samples using liquid chromatography-mass spectrometry. RESULTS: In rats with induced atrophic gastritis, hyperemia and acute erosions of the gastric mucosa, as well as microscopic signs of non-active chronic body gastritis and non-active antral atrophic gastritis were found. Amoxicillin concentration in washes from the gastric mucosa was significantly (p 0.01) higher in rats of experimental group than in control group at all time points (30, 60, 120, 240 min after drug infusion). The lowest mean amoxicillin concentration in gastric juice was observed in patients with antral atrophy (p 0.01). The maximum amoxicillin concentration in gastric secretion was found at the 180th min of aspiration in patients with atrophy of gastric mucosa, while in patients of the group of comparison it was found at 30-120th min of aspiration. CONCLUSIONS: Acute gastric mucosa erosions enhance amoxicillin delivery to gastric lumen in rats. Atrophy of antral mucosa more than in the corpus is characterized by decreased amoxicillin transfer from systemic bloodstream to gastric lumen in patients after oral amoxicillin intake. The gastric mucosa atrophy should be taken into consideration while predicting the efficacy of H. pylori eradication therapy in patients with chronic gastritis.