Prospective randomized trial of 100u vs 200u botox in the treatment of idiopathic overactive bladder

Aim: To evaluate the clinical outcomes of two different doses of BTX-A in patients with refractory idiopathic overactive bladder.

Patients and methods: Thirty nine patients with refractory idiopathic overactive bladder from 1/1/2008 till 30/3/2009 were evaluated in a tertiary care hospital. Patients were evaluated using urodynamic studies, voiding diary, UDI-6 and IIQ-7 questionnaires prior to being prospectively randomized (alternate randomization) to the BTX-A applications and three months after treatment. Voiding diary and residual volume were followed two weeks later. All patients received intradetrusorial injections of BTX-A (Botox, Allergan, Irvine, CA) of 100u or 200u under cystoscopic control on an outpatient basis. The primary endpoint was assessed for the improvement of urodynamic parameters and adverse events at three months after the initial treatment. Secondary end points included urinary frequency, urgency and UUI episodes as assessed by voiding diary and QoL.

Results: Eleven patients were enrolled to each arm of the study. There were no significant differences in demographic characteristics between the two groups. Urodynamic assessment at the end of the third month showed significant improvement in urodynamic variables in both groups. There was no statistically significant difference in urodynamic parameters and in the voiding diary between the two groups. QOL was significantly improved in both groups with no statistically significant difference between the different doses. Only three patients developed acute urinary retention.

Conclusion: BTX-A at 100u and 200u appears to improve symptoms, urodynamic parameters and QoL with no statistical significance between the two groups.