Role of botulinum toxin-A in refractory idiopathic overactive bladder patients without detrusor overactivity

To evaluate the efficacy of intradetrusor botulinum toxin-A (BTX-A) in idiopathic overactive bladder patients (OAB) refractory to anti-muscarinic therapy, without detrusor overactivity (DOA) on urodynamics.

Patients with refractory idiopathic OAB without DOA on urodynamics were prospectively enrolled. Subjects completed a 3-day voiding diary (3-VD), urogenital distress inventory-6 questionnaire (UDI-6) and graded their quality of life on a 10-cm visual analog scale (VAS) prior to study enrollment and at week 12 postinjection. All patients underwent multichannel urodynamics at study enrollment and 12 weeks postinjection. Improvement was analyzed based on 3-VD, UDI-6 questionnaire, VAS scores, and urodynamic parameters at week 12 postinjection compared to study enrollment.

The study included 32 patients. Mean ± SD age was 56 ± 16. There were 27 women and 5 men. Nineteen patients had OAB without incontinence (OAB-dry) and 13 patients had OAB with incontinence (OAB-wet). In OAB-dry patients, mean ± SD urinary frequency dropped from 24 ± 11 to 10 ± 4 by week 12. In OAB-wet patients, mean ± SD urge incontinence episodes dropped from 7.9 ± 5 to 0 ± 2.6 by week 12. Mean UDI-6 and VAS scores improved significantly in both groups by week 12 (P = 0.0001). On comparing urodynamic parameters, OAB-wet patients showed significant decrease in maximum detrusor pressure during the voiding phase at week 12 compared to baseline values (P = 0.02).

Refractory idiopathic OAB patients without DOA on urodynamics may benefit from intradetrusor BTX-A.