Effectiveness of oral beta-lactam antibiotics in acute bacterial prostatitis: A retrospective study

Fluoroquinolones (FQs) and trimethoprim-sulfamethoxazole (TMP-SMX) are first-line outpatient treatments for acute bacterial prostatitis (ABP). Owing to the increasing antimicrobial resistance and side effects of FQs and TMP-SMX, beta-lactams (BLs) are the recommended option; however, few reports have demonstrated the usefulness of oral BLs compared with FQs or TMP-SMX. Here, we evaluated the effectiveness of oral BLs compared with that of FQs and TMP-SMX after initial intravenous antibiotic therapy.

This single-center retrospective observational study included adult men with ABP who received intravenous antibiotic therapy and were subsequently switched to oral therapy. The causative organism was Enterobacteriaceae. The primary outcome was the clinical cure rate. The secondary outcomes included Clostridioides difficile infection, sepsis, and all-cause mortality within 30 days.

Overall, 66 episodes in 65 patients met the eligibility criteria; 15 and 51 patients were included in the BL and FQ/TMP-SMX groups, respectively. Clinical cure was observed in 61.5% of the patients in the BL group and in 87.2% of the patients in the FQ/TMP-SMX group. A significant difference was observed for clinical cure with FQs/TMP-SMX (p = 0.049). However, this difference was not noted in the sensitivity analysis, and oral treatment duration between groups was suspected as a major confounder. No cases of C. difficile infection, sepsis, or all-cause mortality were observed.

When initiating intravenous antimicrobial therapy for ABP and subsequently switching to oral antimicrobials, BLs may not demonstrate the same clinical effectiveness as FQs or TMP-SMX. Larger studies that adjust for background factors are necessary.