Optimized Amoxicillin Dosing is Associated with Higher Helicobacter pylori Eradication in Metabolic and Bariatric...

Patients with obesity are frequently underrepresented in Helicobacter pylori (H pylori) trials. In this population, physiological alterations including increased volume of distribution of hydrophilic antibiotics such as amoxicillin may result in subtherapeutic mucosal concentrations with standard fixed doses, contributing to suboptimal eradication rates in Metabolic and Bariatric Surgery (MBS) candidates. We evaluated the effectiveness and safety of a weight-adjusted amoxicillin regimen for improving H. pylori eradication in patients with obesity scheduled for MBS.

This multicenter retrospective cohort study included adult MBS candidates with histologically confirmed H pylori infection. Patients received either standard fixed-dose quadruple concomitant therapy or an optimized regimen in which amoxicillin was administered at 50 mg/kg/day based on adjusted body weight, not exceeding 6 g/day. Eradication was confirmed by ¹³C urea breath test performed 6-8 weeks after treatment. Adverse events and adherence were systematically recorded.

A total of 177 patients were analyzed: 129 received fixed-dose therapy and 48 received optimized amoxicillin dosing. Eradication was achieved in 89.6% of patients in the optimized group compared with 68.2% in the fixed-dose group (p < 0.05). Optimized dosing was associated with a fourfold increase in the odds of eradication (OR 4.01; 95% CI 1.48-10.86). The safety profile was favorable, with predominantly mild adverse events and no significant differences between groups.

Optimized amoxicillin dosing was associated with higher H pylori eradication rates without an apparent clinically significant adverse events in MBS candidates. These findings question the adequacy of fixed-dose regimens in this population and support individualized antimicrobial strategies to optimize preoperative eradication.