Antibiotics for UTI Prevention After Intradetrusor OnabotulinumtoxinA Injections

Importance Urinary tract infections (UTIs) occur in 8.6% to 48.1% of patients after intradetrusor onabotulinumtoxinA injections. Objective The objective of this study was to evaluate both choice and duration of antibiotic prophylaxis on the incidence of UTI within 30 days after in-office onabotulinumtoxinA injections. Study Design We included a single-site, retrospective cohort of 305 patients with overactive bladder or bladder pain syndrome receiving postprocedure prophylactic antibiotics for in-office, 100-unit intradetrusor onabotulinumtoxinA injections from 2019 to 2023. Categories of antibiotic prophylaxis compared included (1) nitrofurantoin 100 mg twice daily for 3 days, (2) nitrofurantoin 100 mg twice daily for 5 days, (3) trimethoprim-sulfamethoxazole 160 mg/800 mg twice daily for 3 days, and (4) “other regimens.” Primary outcome was incidence of UTI within 30 days. Variables were compared via χ² test. Crude/adjusted odds were estimated using binary logistic regression. Results Incidence of UTI was 10.4% for 3-day nitrofurantoin, 20.5% for 5-day nitrofurantoin, 7.4% for 3-day trimethoprim-sulfamethoxazole, and 25.7% among “other regimens” (P = 0.023). Differences among primary regimens were substantial but not statistically significant: 3-day trimethoprim-sulfamethoxazole had 31% lower odds of UTI versus 3-day nitrofurantoin (odds ratio [OR], 0.689; P = 0.518). Compared with 3-day nitrofurantoin regimen, the 5-day nitrofurantoin regimen had twice the odds of UTI (OR, 2.22; P = 0.088). Those receiving “other regimens” had nearly 3 times the odds of UTI (OR, 2.98; P = 0.018). Results were similar adjusting for age and race. Overall urinary retention rate was 1.97%. Conclusions Prophylactic antibiotic choice and duration of treatment potentially affect UTI incidence after in-office, intradetrusor onabotulinumtoxinA injections. Nitrofurantoin and trimethoprim-sulfamethoxazole for 3 days have the lowest UTI incidence.