Urologists from Guy's Hospital and King's college conducted a randomized, double-blind placebo trial on 34 patients, averaging 50 years of age. All of the patients were either unable to tolerate or failed to respond to anticholenergic drugs traditionally used to help manage overactive bladder. Of the participants, 7 men and 9 women received Botox injections, while 8 men and 10 women received the placebo. "The Botox or placebo injections were administered using a flexible injection needle inside a cystoscope, a long tube that enables urologists to see inside the bladder," explains consultant urological surgeon Prokar Dasgupta from Guy's Hospital and King's College London School of Medicine. "This minimally invasive technique involved 20 injections - five in the midline posterior bladder wall, five in the left lateral wall, five in the right lateral wall and five across the dome of the bladder. In all, 200ml of Botox or placebo was administered."

The patients were assessed at the beginning of the study, as well as at 12 and 24 weeks following the injection. Each participant completed the King's Health Questionnaire, which was developed in the late 1990s to assess women with urinary incontinence. The higher the score, the lower the quality of life. Those patients who received the Botox injections reported significant improvements in terms of a number of quality of life factors. Moreover, at 12 weeks, the study was "unblinded" so that both patients and clinicians knew who had received the injections. During this extended period, participants exhibited further improvements, including improved sleep, greater energy and improved personal relationships.

Another study conducted by the Mayo Clinic in Jacksonville, FL on 25 women suffering from severe incontinence also showed that Botox appears to be a safe and potentially promising method of treatment. Similar to the UK study, all 25 participants had failed at least two oral anticholenergic therapies and were at the end of the line in terms of oral medical treatment options. However, unlike the UK study, the Mayo Clinic team delivered Botox to the bladder using direct instillation of a solution containing botulinum toxin Type A (Botox) and dimethyl sulfoxide.

According to the study authors, this novel delivery method has distinct advantages over the current standard approach of injecting the agent into the detrusor muscle through a cystoscope-based procedure. "Once the efficacy of botulinum toxin Type A for use in overactive bladder had been established, our team started looking for a way of delivering the agent that would not require a cystoscope or anesthetic," says first author Steven P. Petrou, MD, professor of urology at Mayo Clinic. "The idea for this less-invasive approach took its roots from collegial discourse and a review of the literature where DMSO was used as a carrier agent with other bladder-based medicines."

News Release: For people with overactive bladders, Botox injections can significantly improve quality of life http://www.medicalnewstoday.com/printerfriendlynews.php?newsid=153348June 11, 2009

News Release: Botox cocktail appears to ease overactive bladder http://www.plasticsurgerypractice.com/eReport/2009-07-06_01.asp