Broad-Spectrum Antibiotics Are Overused in Treatment of CA-cIAI

Broad-spectrum antibiotics are overused in the treatment of community-acquired complicated intra-abdominal infection (CA-cIAI), according to a new study.

The retrospective, observational study, published in Open Forum Infectious Diseases, aimed to determine treatment patterns and examine compliance with guidelines discouraging use of anti-pseudomonal β-lactams and fluoroquinolones for CA-cIAI. Use of broad-spectrum antibiotics increases the risk of Clostridium difficile infection and antibiotic resistance. Fluoroquinolones also are associated with adverse reactions, including increased risk of aortic aneurysm.

“Overall, overuse of non-guideline concordant broad-spectrum anti-pseudomonal antibiotics, namely TPZ and fluoroquinolones, was found to be commonplace among lower risk patients with CA-cIAIs like acute appendicitis with peritonitis,” Thomas P. Lodise Jr., PharmD, PhD, professor, pharmacy practice, Albany College of Pharmacy and Health Sciences told Contagion^®. “Similar outcomes across varying empiric treatment regimens suggest there is an opportunity to use narrow-spectrum antibiotic therapies and limit the use of antibiotics with anti-pseudomonal activity.”

Data from the Premier Healthcare Database of 46,722 lower-risk adults hospitalized with cIAI between October 2015 and December 2017 was reviewed. Acute appendicitis with peritonitis was the most common diagnosis, affecting 59.7% of patients. The study found that 54% received piperacillin/tazobactam, 20% received a fluoroquinolones (ciprofloxacin and levofloxacin), 11% received ceftriaxone, and 7% received ampicillin/sulbactam.

“I knew there would be use of TPZ and fluoroquinolones but I did not anticipate that ~75% of lower risk patients with CA-cIAIs would have received TPZ (50%) or fluoroquinolones (25%),” Lodise said.

Outcomes were similar across all treatments; however, the study wasn’t designed to compare outcomes by treatment, and didn’t perform inferential statistics. Less than 1% of patients died, 89% were discharged home, 9.5% were transferred to another hospital, and about 10% had a readmission within 30 days. Average length of hospital stay was 4 days, and average cost was $12,345.

Limitations of the study include that it didn’t include microbiologic data, and it is possible that some patients included in the study received a board-spectrum antibiotic to treat a suspected or documented antibiotic resistant pathogen. Allergy information also wasn’t collected, opening the possibility that some of the patients who received a fluoroquinolone were intolerant to beta-lactams. Still, even accounting for the possibility of misclassified patients, the study showed a significant number of lower-risk patients receiving treatment out of line with guidelines.

“The findings from this study can serve as the basis for an antimicrobial stewardship initiative to reduce the use of broad-spectrum antibiotics among lower risk patients with CA-cIAI,” Lodise stated. “Decreasing use of inappropriate broad-spectrum antibiotics is consistent with the CDC’s core elements for antibiotic stewardship and could potentially help to decrease incidence of developing CDI and subsequent antibiotic-resistant infections.”

Antimicrobial stewardship programs have expanded as health care officials continue to fight the emergence of drug-resistant pathogens and other risks of overtreatment. Antimicrobial stewardship experts recently explored myths and realities of antibiotics use, exploring such factors as cognitive biases that affect how antibiotics are used.