What is the ideal antibiotic prophylaxis for intravesically administered Botox injection? A comparison of two different regimens.

INTRODUCTION: Onabotulinum toxin A (Botox®) administered intravescially is an effective treatment for idiopathic detrusor overactivity, of which urinary tract infections (UTIs) are a common complication. The purpose of this study was to compare two prophylactic antibiotic regimens with the goal of decreasing UTI rates following intravesically administered Botox® injection.

MATERIALS AND METHODS: A retrospective review of two groups of patients undergoing intravesically administered Botox® injections was performed-one with idiopathic and one with neurogenic detrusor overactivity. One group received a dose of ceftriaxone intramuscularly (IM) at the time of Botox® injection, and a second group received a 3-day course of a fluoroquinolone orally starting the day before the procedure. The rate of postprocedure UTI was examined using a χ2 test. A secondary analysis was performed using logistic regression modeling to test the association between clinical characteristics and antibiotic regimen and risk of postprocedure UTIs.

RESULTS: Botox® injections were performed on 284 patients: 236 received a single dose of ceftriaxone IM and 48 received 3 days of a fluoroquinolone orally. The UTI rate was significantly lower in the fluoroquinolone group (20.8%) vs. the cephalosporin group (36%), p = 0.04. Predictors of postprocedure UTIs included single dose of antibiotics IM [odds ratio (OR 2.80, p = 0.02] and a positive preprocedure urine culture (OR 1.31, p = 0.03).

CONCLUSIONS: We found a significantly lower rate of UTIs when patients received a 3-day course of a fluoroquinolone orally as opposed to a single dose of a third-generation cephalosporin IM. Patients with a positive preprocedure culture might benefit from an even longer duration of antibiotics at the time of Botox® injection.