Assessment of Anticholinergic Use After Fading of BTX-A Effects in Refractory Idiopathic Overactive Bladder: A Prospective Blinded Randomized Trial

PURPOSE: To evaluate the efficacy and safety of re-treatment with anticholinergics on refractory idiopathic overactive bladder (OAB) previously treated with intravesical botulinum neurotoxin type A (BTX-A) injections. METHODS: One hundred patients were initially managed by intravesical injections of 100 IU of BTX-A. After the effects of BTX-A faded, patients were randomized into 2 groups: group A patients received solifenacin (10 mg) for 12 weeks (study group), while group B patients received placebo treatment for 12 weeks (control group), then subsequently received solifenacin (10 mg) for another 6 weeks. All patients underwent preoperative urodynamic testing. Patients were asked to complete the validated overactive bladder symptoms score (OABSS) and incontinence quality of life (I-QoL) instruments after the effects of intravesical BTX-A faded and at 12 weeks of follow-up. Univariate and multivariate analyses of the factors affecting treatment response were conducted. RESULTS: At 12 weeks of follow-up, in group A, all OABSS items, including the total score, had improved significantly (P<0.0001). Group A had lower frequency and amplitude of detrusor overactivity and detrusor leak point pressure (P<0.0001, P=0.03, and P=0.01, respectively). Cystometric capacity also increased significantly (P=0.007), as did all I-QoL parameters. In a comparison of patients with failed treatment and patients with successful treatment, female sex, repeated intravesical BTX-A injections, and increased bladder capacity were statistically significant (P=0.001, P=0.0001, and P=0.002, respectively). Repeated intravesical BTX-A injections and increased bladder capacity were independent factors predicting treatment success. CONCLUSIONS: In patients with refractory idiopathic OAB, reuse of anticholinergics could be an effective treatment option in patients after the effects of BTX-A fade. Repeated intravesical BTX-A injections and increased cystometric capacity could affect treatment response.