• adverse events;
  • detrusor overactivity;
  • onabotulinumtoxinA;
  • overactive bladder

Objectives: Intravesical injection of onabotulinumtoxinA (i.e. Botox) provides effective treatment for overactive bladder. However, treatment-related adverse events (AEs) remain problems. This study investigated the effect of AEs after onabotulinumtoxinA injection on the success rate for idiopathic detrusor overactivity (IDO).

Methods: A total of 174 patients who received the first single intravesical onabotulinumtoxinA 100U injection for refractory IDO were included. The onabotulinumtoxinA related AEs including acute urinary retention (AUR), large postvoid residual (PVR, ≥150 mL), difficult urination, urinary tract infection, gross hematuria and general weakness were recorded. The success rate was determined based on patient perception of bladder condition improved by two scales. The short-term (3 months) and long-term (up to 24 months) success rates were analyzed according to the occurrence of these AEs.

Results: A successful outcome was reported by 138 (79.3%) patients at 3 months. AUR occurred in 12 (6.9%) patients, large PVR developed in 81 (46.6%) and 73 (42%) needed straining to void. Gross hematuria occurred in 17 (9.8%) patients, urinary tract infection developed in 27 (15.5%) and general weakness was noted in 6 (3.4%). The occurrence of AUR did not affect the therapeutic results. Patients having large PVR and difficult urination had a significantly higher success rate at 3 months. Long-term success rates up to 24 months showed no significant difference between patients with and without AEs.

Conclusions: AEs after intravesical 100U onabotulinumtoxinA for IDO were frequently encountered. However, the occurrence of AUR, large PVR or difficult urination did not affect the final therapeutic outcome.