For the past 10 years, research has focused on how to properly and appropriately apply botulinum toxin to the urinary tract. Most commonly known as BOTOX, the toxin acts to prevent the release of the neurotransmitter acetylcholine from the nerve ending onto the muscle. By preventing muscle contraction, BOTOX acts to paralyze the muscle being treated that is abnormally spastic, or abnormally overactive. Directed by injection into the abnormal muscle, only that muscle is "treated" with paralysis, thereby giving relief to the patient experiencing muscle disorder.
For urology, a very common bladder muscle disorder is overactive bladder. There are a variety of reasons the bladder can be overactive, spastic, or contract abnormally. Five months ago, the FDA approved the use of BOTOX treatment for bladder overactivity from neurological disorders. Any type of neuropathy that leads to bladder overactivity and incontinence of urine would qualify for treatment. These would include bladder incontinence from stroke, multiple sclerosis, back nerve injury, spinal cord injury, Parkinson's disease, and others, when medication and other measures fail to control incontinence. It is not approved for "plain old" overactive bladder, a common disorder of women from age, menopause, or hysterectomy. Treament is carried out by injecting BOTOX directly into the bladder muscle via a cystoscope, while looking in the bladder.
In multiple studies, BOTOX injection has been shown to be effective in curbing incontinence, and bladder overactivity in neurologically affected bladders. The effect can last typically for 6-9 months. Retreatment is possible and often equally effective. In the 5 largest published studies the following results can be summarized:
Leaking controlled in at least 73% of patients
Frequency of incontinence episodes decreased by 32-90%
Bladder capacity increased significantly
Duration of treatment averaged 6-9 months
Those who may not respond to treatment are those with shrunken, thickened or scarred bladders.
The most common side effects of treatment were urinary tract infection, blood in the urine and incomplete bladder emptying. Rare side effects include generalized muscle weakness and insomnia, which were transient.