BackgroundUrinary tract infections (UTIs) caused by extended spectrum beta-lactamase (ESBL) producing pathogens have increased and are treated with carbapenem in general. Carbapenem use is associated with prolonged hospitalization or daily outpatient visit. The aim of this study was to investigate patients with UTIs by ESBL-producing pathogens for early discharge using an old oral antibiotic, trimethoprim-sulfamethoxazole (TMP-SMX), which is susceptible to ESBL-producing pathogens.MethodsData on UTIs caused by ESBL-producing pathogens from a single tertiary hospital were collected retrospectively. Patients who had been treated with intravenous carbapenems or oral TMP/SMX were included. Patients’ clinical and microbiological outcomes were compared between oral TMP/SMX and ertapenem treatment groups.ResultsA total of 103 patients were included, 21 of whom had been treated with TMP/SMX, whereas 82 with ertapenem. Clinical outcomes between the two groups were not significantly different (TMP/SMX: 90.5%; ertapenem: 84.1%, p = 0.73). The microbiological cure rate was higher in the TMP/SMX group than in the ertapenem group (90.5% vs 58.5%, respectively, p = 0.01). The mean duration of hospitalization was significantly shorter in the TMP/SMX group than in the ertapenem group (8.00 ± 10.50 days vs 14.00 ± 37.00 days, p = 0.07). The mean duration of antibiotic treatment was longer in the ertapenem group than in the TMP/SMX group (16.45 ± 4.77 vs 12.76 ± 5.37 days, p = 0.006).ConclusionFor susceptible pathogens, TMP/SMX may enable early discharge as an effective oral antibiotic treatment option for UTIs caused by ESBL-positive pathogens. Additionally, use of oral antibiotics can shorten hospital stays and reduce medical costs.