Time of onset and factors associated with delayed response post intradetrusor injection of onabotulinumtoxin a in patients with neurogenic and idiopathic overactive bladder syndrome

OBJECTIVE: The objective of this study was to determine risk factors for delayed response in patients with neurogenic and idiopathic overactive bladder (OAB) after intradetrusor onabotulinumtoxin A injection. SUBJECTS AND METHODS: This is a retrospective study that included 87 patients who underwent onabotulinumtoxin A intradetrusor injection from October 2011 to November 2019. Patients were followed up at 2, 4, and 12 weeks post intervention in the outpatient clinic and over the phone. The data of patients with early response were compared with those with late response using univariate and multivariate analyses. RESULTS: The study included 87 patients. The mean age was 41 ± 15.3 standard deviation, and 69% of the participants were female. Fifty-one percent were diagnosed with neurogenic OAB. A median response time to onabotulinumtoxin A injection of 7 days was demonstrated, and patients who responded during the first 7 days post procedure were considered early responders. Independent predictors for late response include diabetes (Relative risk: 3.89, P = 0.018, and 95% confidence interval [CI]: 1.26–11.98), >1 BTX-A session (Relative risk: 4, P = 0.011, and 95% CI: 1.38–11.6), and wet OAB (RR: 9.94, P = 0.002, and 95% CI: 2.31–42.17). CONCLUSIONS: The median time of onset post intradetrusor injection of onabotulinumtoxin A was found to be 7 days. Diabetes mellitus, wet OAB, and <1 Botox sessions were independent risk factors for late onset of response.