# Efficacy and Safety of Oral Neomycin for the Decolonization of Carbapenem-Resistant Enterobacterales: An Open-Label Randomized Controlled Trial

## TL;DR

A study tested oral neomycin to reduce gut colonization of antibiotic-resistant bacteria, finding short-term effectiveness but temporary results.

## Contribution

This is the first open-label randomized trial evaluating neomycin's efficacy for decolonizing carbapenem-resistant Enterobacterales in humans.

## Key findings

- Neomycin reduced CRE colonization by 42.8–53.8% by day 7, compared to controls.
- CRE colonization rates in the neomycin group rebounded to match controls by day 14.
- Neomycin caused only mild and temporary gastrointestinal side effects.

## Abstract

Background: Patients with carbapenem-resistant Enterobacterales (CRE) in the gastrointestinal (GI) tract are at risk for subsequent infections and transmission, necessitating contact precautions. Neomycin has shown in vitro activity against CRE in 66–85% of isolates. This study evaluated the efficacy and safety of neomycin for CRE decolonization. Methods: In this open-label randomized controlled trial, stool/rectal swab samples from high-risk patients were collected and tested for CRE colonization in the GI tract. Patients who had CRE and met eligible criteria were divided into a neomycin group (n = 26; treated with 4.2 g/day neomycin for 5 days) and a control group (n = 26). CRE detection in stool/rectal swabs was performed on days 7 ± 2 and 14 ± 2. Results: The two groups’ baseline characteristics were similar. CRE presence on day 7 ± 2 was significantly lower in the neomycin group (46.2%) than in the control group (80.8%, p = 0.01). Efficacy of neomycin (4.2 g/day for 5 days) for CRE decolonization was 42.8–53.8% by day 7. By day 14 ± 2, the CRE rate in the neomycin group had risen to align with the control group’s rate (73.1% vs. 61.5%, p = 0.56). The neomycin group experienced mild, temporary, gastrointestinal side-effects. Conclusions: Neomycin effectively reduced CRE colonization on day 7 ± 2, but its impact waned by day 14 ± 2. This suggests that neomycin dosage was too low and the duration of treatment was too short for lasting CRE decolonization.