Urinary tract infections (UTIs) are a significant concern in patients undergoing Onabotulinum Toxin A (Botox) injections for refractory idiopathic overactive bladder. Post procedure UTIs can impact treatment outcomes and have a significant negative effect on patient well-being. Yet to date there continues to be wide variation in the reported prevalence of UTI following intradetrusor botox injections with rates varying between 8% and over 35% (1). A variety of risk factors have also been suggested including age, gender, comorbidities and factors related to bladder emptying. 

Given the impact UTI have on outcomes, real world data is vital in both accurate identification of risk factors and to allow appropriate patient counselling. This study aims to collective prospective real world data on the incidence and causes of UTI following botox treatment for idiopathic OAB.

A multicentre, prospective observational study of all adult patients undergoing cystoscopic botulinum toxin A injection to the detrusor for the treatment idiopathic detrusor overactivity. Patients were recruited from three centres in South London.  143 patients were identified from hospital waiting lists and consented. Inclusion criteria were adult patients undergoing botox injections for idiopathic OAB syndrome refectory to medical treatment. Patients were excluded if they had a history of recurrent urinary tract infections defined as 3 or more in the last year. Study protocol did not determine a specific technique for delivery of botulinum toxin a which was conducted according to individual study site protocol either under local or general anaesthetic. Patients completed ICIQ-OAB prior to treatment. Preoperative testing for the presence of a urinary, peri-procedure and post procedure antibiotic prophylaxis and/or treatment were decided according to local guidelines at participating centres. Details of the patients past medical history and botox treatment details were recorded.

Patients were followed at at 6 weeks and 6 months with a telephone call to check for any history of urinary tract infection, antibiotic treatment given and requirement for intermittent self-catheterisation. Patient were invited to completed ICIQ-OAB questionnaire again at 6 weeks. 

Statistical analysis was performed using Python 3.12.2. Potential risk factors for UTI at 6 weeks were evaluated using multivariate binomial logistic regression analysis.

143 participants were enrolled in the study and UTI data was available for 106 patients. Mean ± standard deviation age of all participants was 55.9 ± 15.9. 66% of participants were female. 29% of participants (n=28) were receiving their first treatment. The majority of participants (73%) were treated with 100 units of Botox. Prevalence (n) of UTI at 6 weeks and 6 months was 12% (92) and 27% (19) respectively. 

Logistic regression analysis was performed for key potential risk factors for development of UTI (age, gender, history of UTI in the last year, history of diabetes, menopause status). See table 1 for results. R2 = 0.17. ISC at 6 weeks was significantly associated with the presence of UTI.

The results from this real world prospective study with a large and diverse cohort of patients have shown high rates of UTI at 6 weeks and 6 months in excess of those commonly quoted in patient information literature. In contrast to previous studies the only significant risk factor was the need for participants to self catheterise at 6 weeks with an increase in risk of almost two times.. Whilst age and menopause were approaching significance the results from this study do not conclusively demonstrate that they are linked to developing a UTI.

This multicentre prospective observational study provides valuable insights into the incidence and risk factors associated with urinary tract infections (UTIs) following Onabotulinum Toxin A (Botox) treatment for refractory idiopathic overactive bladder (OAB). The prevalence of UTIs at 6 weeks and 6 months post-treatment was found to be 12% and 27% respectively, highlighting the significant burden of UTIs in this patient population.

While other factors such as age, gender, history of UTI, history of diabetes, and menopause status did not show significant associations in this study, it is essential to consider the multifactorial nature of UTI development. Factors such as bladder function may also play roles in UTI risk and should be further investigated in future studies.

Clinically, these findings underscore the need for personalized approaches to patient care following Botox treatment for OAB. Healthcare providers should consider the individual patient's risk factors, especially the need for ISC, when planning post-procedure management strategies.

A comparison of antibiotic prophylaxis regimens to decrease the risk of post-procedure urinary tract infection after onabotulinum toxin A injection  Jennifer A Bickhaus  1   2 , Monique Vaughan  3 , Tracy Truong  4 , Yi-Ju Li  4 , Nazema Y Siddiqui  3 Affiliations  expand PMID: 31989204  PMCID: PMC7498079  DOI: 10.1007/s00192-020-04230-7

Continence 12S (2024) 101518
DOI: 10.1016/j.cont.2024.101518