# In a bind: a quality improvement project for reducing fluoroquinolones drug–drug interactions with multivalent cations

## TL;DR

A quality improvement project reduced harmful drug interactions between fluoroquinolones and multivalent cations, but the issue wasn't fully eliminated.

## Contribution

A bundle of interventions was implemented and evaluated to reduce fluoroquinolone–cation drug interactions in clinical practice.

## Key findings

- Co-administration of fluoroquinolones and multivalent cations within 2 hours dropped from 62% to 22% after interventions.
- The intervention bundle reduced but did not eliminate the risk of this drug interaction.
- Fluoroquinolone–cation interactions are an independent risk factor for resistance and warrant stewardship attention.

## Abstract

Fluoroquinolone (FQ) co-administration with multivalent cations can decrease the bioavailability of the FQ significantly. This interaction is an independent risk factor for FQ resistance, which is a concern as more clinical trials and guidelines support routine use of oral antimicrobials.

We examined the incidence of FQ drug–drug interactions (DDIs) in a quality improvement study after implementation of a bundle of interventions including nursing education, updated medication administration record (MAR) comments and new administration times.

In the subgroup of patients (n = 101) who had a multivalent cation administered on the same day as a FQ, co-administration within 2 hours of the FQ was higher in the pre-intervention group as compared to the post-intervention group (62% versus 22%, P < 0.001).

The bundle of interventions decreased but did not eliminate the interaction. With the interaction as an independent risk factor for resistance and increasing use of oral antibiotics, stewardship programmes should consider implementing similar interventions.