Risk of urinary tract infection after detrusor botulinum toxin A injections for refractory neurogenic detrusor overactivity in patients with no antibiotic treatment.

Objective: To determine if antibiotic prophylaxis is required for intradetrusor botulinum toxin A (BoNT-A) injections.

Patients And Methods: This was a prospective non-randomized study. Inclusion criteria were adult patients with neurogenic detrusor overactivity who failed anticholinergic-based first-line treatment and had sterile urine culture 7 days before injections, a negative dipstick test on the day of the injections, and were performing clean intermittent self-catheterization. Injections were performed using a rigid cystoscope, under local anaesthetic. Patients received BoNT-A as either Botox® (Allergan Inc., Irvine, CA, USA) 300 U in 30 sites or Dysport® (Ipsen Ltd, Ipsen, Paris, France) 750 U in 20 sites. Urine culture was done 6 days and 6 weeks after the injections. If urinary tract infection (UTI) was suspected, a physician performed a complete physical examination. The primary outcome criterion was the occurrence of UTI during the first week after injections.

Results: In all, 42 patients (22 women, 20 men) with a mean (sd) age 45.3 (16.4) years were included. A symptomatic UTI occurred during the first week after the injections in three patients (7.1%). The urinary colonization rate was 31% and 26% at 6 days and 6 weeks after injection, respectively. The most common bacterium was Escherichia coli (62.5%). There were no differences between 20 and 30 injection sites or between the sexes.

Conclusion: The rate of UTI after intradetrusor injections of BoNT-A was 7.1%. The most frequent bacterium involved was Escherichia coli. These results indicate that antibiotic prophylaxis for intradetrusor BoNT-A injections seems necessary.