Efficacy and safety of onabotulinumtoxinA injection in patients with refractory overactive bladder: First multicentric study in Turkish population.

Aims: To investigate the efficacy and safety of intradetrusor onabotulinumtoxinA (onaBoNT-A) injection in patients with overactive bladder (OAB) refractory to antimuscarinic treatment.

Methods: A total of 80 patients with OAB symptoms were enrolled in this prospective multicenter study and received 100 U intradetrusor onaBoNT-A injection.The changes from baseline in the frequency of voiding, urge urinary incontinence (UI) and urge episodes, mean and maximum bladder capacities, uroflowmetry, post-void residual urine volume (PVR), quality of life score, and treatment benefit scale score were assessed. The need for a second injection,and treatment-related adverse events were also examined postoperatively.

Results: OnaBoNT-A injection significantly decreased the UI episodes(P = 0.0001), the mean voiding frequency (P = 0.0001), and the urgency episodes (P = 0.0001) in the third month compared to baseline. Similarly, the mean bladder capacity, and maximal bladder capacity were increased (P < 0,05). The quality of life scores improved by 57.1% compared to the pre-treatment rate (P = 0,0001). No significant change was observed in the PVR or maximum flow rate. Urinary retention developed in 3 (3.75%) patients and urinary infection and transient hematuria were observed in five patients (6.25%) each. The UI episodes, voiding frequency and urgency episodes were significantly lower at the 9th month than at baseline (all P = 0.0001). Overall 67% of the patients continued to experience benefits from the injection. Sixteen patients (20%) required a second injection in the third month. Eight patients were lost to follow-up at the last visit in the 9th month, and 34 of the remaining 56 patients required a second injection at the 9th month. Cumulatively, 50 (63%) patients needed re-injections.

Conclusions: Our results demonstrated that the onaBoNT-A injection produced significant improvement in all OAB symptoms with a low incidence of treatment related adverse events.