Reductions in inpatient fluoroquinolone use and postdischarge Clostridioides difficile infection (CDI) from a systemwide antimicrobial stewardship intervention

Fluoroquinolone stewardship at a community health system: A decade in review

OBJECTIVE

To describe inpatient fluoroquinolone use and susceptibility data over a 10-year period after the implementation of an antimicrobial stewardship program (ASP) led by an infectious diseases pharmacist starting in 2011.

DESIGN

Retrospective surveillance study.

SETTING

Large community health system.

METHODS

Fluoroquinolone use was quantified by days of therapy (DOT) per 1,000 patient days (PD) and reported quarterly. Use data are reported for inpatients from 2016 to 2020. Levofloxacin susceptibility is reported for Pseudomonas aeruginosa and Escherichia coli for inpatients from 2011 to 2020 at a 4 adult-hospital health system.

RESULTS

Inpatient fluoroquinolone use decreased by 74% over a 5-year period, with an average decrease of 3.45 DOT per 1,000 PD per quarter (P < .001). Over a 10-year period, inpatient levofloxacin susceptibility increased by 57% for P. aeruginosa and by 15% for E. coli. P. aeruginosa susceptibility to levofloxacin increased by an average of 2.73% per year (P < .001) and had a strong negative correlation with fluoroquinolone use, r = -0.99 (P = .002). E. coli susceptibility to levofloxacin increased by an average of 1.33% per year (P < .001) and had a strong negative correlation with fluoroquinolone use, r = -0.95 (P = .015).

CONCLUSIONS

A substantial decrease in fluoroquinolone use and increase in P. aeruginosa and E. coli levofloxacin susceptibility was observed after implementation of an antimicrobial stewardship program. These results demonstrate the value of stewardship services and highlight the effectiveness of an infectious diseases pharmacist led antimicrobial stewardship program.

Effect of Reduced Fluoroquinolone Use on Cephalosporin Use, Susceptibilities and Clostridioides difficile Infections

Background: Overuse of fluoroquinolones has led to concerning rates of resistance, particularly among Gram-negative organisms. They are also highly implicated as a risk factor for Clostridioides difficile infection, and reports of other serious adverse events led to recommendations to restrict their use. Our health system began targeting the reduction in unnecessary fluoroquinolone prescribing in 2018, aiming to promote their safe and effective use. Broad-spectrum cephalosporins are often used as an alternative to fluoroquinolones. We sought to evaluate whether decreased fluoroquinolone use was associated with increased third- and fourth-generation cephalosporin use and whether these changes in utilization impacted other outcomes, including C. difficile infection (CDI) rates and susceptibilities among Gram-negative organisms. Methods: This retrospective descriptive analysis included adult patients who received a fluoroquinolone or broad-spectrum cephalosporin in a three-year time period across a large healthcare system. The primary objective was to evaluate the change in days of therapy (DOT) of fluoroquinolones and third- and fourth-generation cephalosporins. Secondary objectives included rates of resistance among common Gram-negative organisms, CDI, and analyses stratified by antibiotic indication. Results: Cephalosporin use increased by an average of 1.70 DOT/1000 PD per month (p < 0.001). Additionally, fluoroquinolone use decreased by an average of 1.18 DOT/1000 PD per month (p < 0.001). C. difficile infections decreased by 0.37 infections/10,000 patient-days per month (p < 0.001). Resistance to fluoroquinolones remained stable from 2018 to 2020, and a declining trend was observed in 2021. Conclusion: This study demonstrated that reduced fluoroquinolone use in a large healthcare system was associated with increased usage of broad-spectrum cephalosporins, decreased CDI and improvements in resistance patterns.