Urinary tract infections (UTIs) treated as an outpatient with oral antibiotics are frequently found in emergency rooms. Since antibiotics may be purchased over-the-counter in Mexico, there was concern that possible abuse and overuse of antibiotics in border regions between the United States and Mexico could result in antibiotic resistance patterns that would make some empiric therapies for UTIs less effective. For a study, researchers sought to evaluate the efficacy of antibiotics used to treat outpatient UTIs identified in the emergency room and recommended by the Infectious Disease Society of America (IDSA) guidelines. Data were gathered from a county hospital on the border of the United States and Mexico, in a city with a population of over 2 million. The frequency of isolated urine cultures, the resistance levels of urine pathogens, and prescribing practices were all included in the secondary analysis.

Adult patients who were diagnosed with and treated with UTIs between August 1, 2019, and February 29, 2020, were included in the research. Analysis of the included patients’ culture findings against in vitro-tested antibiotics. The frequency of bacterial isolates, rates of resistance, and prescription patterns were gathered.

Of the 985 patient files evaluated, 520 patients satisfied the inclusion requirements for studying prescription patterns. In examining antibiotic resistance rates, 329 of these positive bacterial culture growths were considered. Amoxicillin/clavulanate, cefdinir, cefuroxime, and nitrofurantoin were oral antibiotics with comparatively lower resistance rates. Oral antibiotics with especially high resistance rates included cephalexin, tetracycline, ciprofloxacin, and trimethoprim-sulfamethoxazole (TMP-SMX). In contrast, cephalexin was the most often given antibiotic for the outpatient treatment of pyelonephritis (50%), and nitrofurantoin was most frequently administered for the outpatient treatment of UTI/cystitis (41.6%).

The results indicated that despite being included in standard IDSA recommendations, fluoroquinolones and TMP-SMX were not the best empiric antibiotics for treating outpatient UTIs in the examined area of the U.S.-Mexico border due to significant resistance rates. Second and third-generation cephalosporins and amoxicillin/clavulanate would be acceptable options given resistance patterns demonstrated in accordance with IDSA allowance for tailoring selection to local resistance, even though they were not listed as first-line agents per current IDSA recommendations. For the treatment of outpatient UTIs in the area, nitrofurantoin seemed to be compatible with guidelines and exhibits a favorable resistance profile.

Reference: sciencedirect.com/science/article/abs/pii/S0735675722005253