March 17, 2021
Consequences of Antibiotic Prophylaxis for Urinary Tract Infections in Older PatientsBy Christopher J. Graber, MD, MPH, FIDSA
Recurrent urinary tract infections (UTIs) can be difficult to manage and are sources of considerable consternation to patients and physicians. While antibiotic prophylaxis is frequently considered as a method to reduce frequency of UTI recurrence, infectious diseases physicians typically recommend against the practice due to concerns for lack of demonstrable efficacy, risk for toxicity, concerns regarding antimicrobial resistance, and risk for Clostridioides difficile infection. A recent study published in Clinical Infectious Diseases reinforces and quantitates these concerns.
The authors reviewed antibiotic prescription data from 2015-2016 from the Ontario Drug Benefits database, which captures all medication dispensed for adults aged 65 and over in outpatient and long-term care settings, and included all patients who received any antibiotic except doxycycline that was prescribed for ≥ 30 days and started within 30 days of a positive urine culture. Each case patient receiving this prolonged antibiotic course was matched to 10 control patients who received shorter antibiotic courses within 30 days of urine culture based on organism isolated, number of positive urine cultures within the prior 12 months, and a propensity score based on baseline demographics, comorbidities, urologic characteristics, and baseline urine culture susceptibilities.
In the study, 3,198 patients receiving prolonged antimicrobial courses were identified with a median duration of 49 days. Nitrofurantoin (44%) was most common, followed by trimethoprim-sulfamethoxazole (17%) and ciprofloxacin (15.7%). Versus matched controls, cases had increased risk of hospitalization for UTI, sepsis, or bloodstream infection (hazard ratio [HR] 1.33; 95% confidence interval [CI] 1.12-1.57) as well as increased acquisition of resistance to not only the agent used for prophylaxis (HR 2.01; 95% CI 1.80-2.24) but also any antibiotic agent (HR 1.31; 95% CI 1.18-1.44). Risk of C. difficile infection was significantly higher among those receiving prolonged courses (HR 1.56; 95% CI 1.05-2.23), as was general medication adverse events (HR 1.62; 95% CI 1.11-2.29).
These findings are of timely importance in the context of increased attention to antimicrobial stewardship efforts in outpatient UTI management and can be used to argue against routine antimicrobial prophylaxis for the vast majority of patients with recurrent UTI.
(Langford et al. Clin Infect Dis. Published online: February 17, 2021.)
