Largest study to date confirms efficacy of botulinum toxin treatment for overactive bladder

Emerging uses of FDA Approved Drugs – by Bruce Sylvester – Results from the largest study yet of the treatment of urinary incontinence with botulinum toxin suggests that the treatment is effective. The finding was reported in March in the journal European Urology.

Investigators in the 4-year study enrolled 240 women diagnosed with severe OAB who had failed to improve with 2 prior different drug treatments.

“We found that a single treatment with botulinum toxin was a very effective treatment for the symptoms of DO,” said Douglas Tincello, MD, Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester, United Kingdom. “Patients were able to pass water 1or 2 times less often during the day, and also noticed far fewer times when they had bad feelings of urgency and had to rush to the bathroom.

“In patients treated with botulinum toxin the times of urgency dropped from 6 a day to less than1 per day,” he said. “Most excitingly, about 4 in 10 women become completely continent again after 6 weeks and a third were still continent again 6 months after treatment. The effects start to wear off after about 6 months or so.”

However, “the treatment is not without complications,” said Dr. Tincello. “About 1 in 8 women had some difficulty emptying their bladder at some time in the 6 months after treatment [due to paralysis of the bladder muscle]. This was treated by teaching the women to use disposable catheters, but the effect does wear off after about 6 months on average.”

The study began in 2006, was the only clinical trial of botulinum toxin in women with OAB at that time, and is the biggest study to date of its kind.

“These findings are important because many doctors have been offering this treatment to patients based on the information from previous studies in people with spinal injuries, and now we have accurate information on exactly what benefit is likely to be noticed after treatment and how common the side effects will be,” said Dr. Tincello. “This will allow patients to decide whether they wish to have this treatment, which at the moment is not licensed for treating OAB.”

The team is currently studying the cost-effectiveness of botulinum toxin for OAB.

“Since the effect of the treatment is so much greater than a 6-month course of tablets, our work may lead to botulinum toxin being used much more widely for this bladder condition and it may turn out be cheaper too,” said Dr Tincello.