Botox® for idiopathic overactive bladder: efficacy, duration and safety. Effectiveness of subsequent injection

Purpose To test the efficacy, duration and safety of 100 U of botulinum toxin type A (BoNT/A) in women affected by idiopathic detrusor overactivity (IDO) and the effectiveness of subsequent injections. Methods In this double centre, prospective study con- ducted from March 2008 to March 2010, we selected women affected by IDO who failed to respond to various antimuscarinic agents, reported intolerable anticholinergic side-effects or contraindication to their use, also without any response to tibial stimulation. Medical history, physi- cal examination, standard urodynamic examination, uri- nalysis, urine culture, a 4-day voiding diary and a quality of life questionnaire were requested for all patients. A total amount of 100 U of BoNT/A were injected into the detrusor muscle. A second injection of BoNT/A was sug- gested to patients who experienced a relapse of initially improved symptoms. Results We enrolled a total number of 68 women. All patients showed significant improvement in urodynamic parameters, clinical features and quality of life, after the first injection of Botox until the 9 months of follow-up. Even after the second injection, with a follow-up of 3 months, we obtained results comparable with the first injection. Side-effects include an increase in post-void residual volume, dysuria and urinary infections. Conclusions We considered the dose of 100U of Botox, for treatment of IDO, as an efficacious and safe solution compared to other therapeutic options, without serious and lasting adverse effects for women, even after a second injection.