Introduction and hypothesis: To evaluate the risk of post-injection urinary tract infection (UTI) after onabotulinumtoxin A (BTX-A) treatment based on the timing of when antibiotic prophylaxis is started.
Methods: This is a retrospective cohort study of 111 women with refractory idiopathic overactive bladder who underwent intradetrusor injection of BTX-A. Two cohorts were identified: (1) 67 women who started antibiotic prophylaxis with ciprofloxacin 1 day prior to injection; (2) 44 women who received antibiotic prophylaxis with ciprofloxacin after injection only. We assessed for post-injection UTI within 90 days after BTX-A. Multivariable logistic regression was performed to adjust for potential confounders.
Results: One hundred eleven women underwent BTX-A. In total, 30 (27%) had a UTI within 90 days; these included 15/67 (22%) of those who started antibiotics 1 day prior to injection and 15/44 (34%) of those receiving antibiotics after injection. While the unadjusted analysis showed no significant associations between timing of antibiotic administration and UTI (OR = 0.56; 95% CI = 0.24, 1.30; p = 0.18), an adjusted analysis showed the pre-procedure antibiotic group had a significant reduction in post-procedure UTI after controlling for age, history of UTI, diabetes, and urinary retention requiring catheterization (OR = 0.23; 95% CI = 0.07, 0.73; p = 0.01).
Conclusions: Starting antibiotics 1 day prior to BTX-A injection decreases the odds of post-injection UTI compared with women who use post-procedure antibiotic prophylaxis over shorter duration. Consideration should be given to beginning antibiotic prophylaxis prior to the procedure and continuing it for 4 total days to decrease the risk of UTI.
Keywords: Antibiotic prophylaxis; Onabotulinum toxin; Overactive bladder; Peri-procedure prophylaxis; Urinary tract infections.