The U.S. Food and Drug Administration has added a “new wrinkle” to the approved uses of Botox (onabotulinumtoxinA), but now permitting doctors to use it to treat adults with overactive bladder who cannot use or do not adequately respond to a class of medications known as anticholinergics.
Overactive bladder is a condition in which the bladder contracts too often or without warning causing urine to leak (incontinence), as well as a sudden and urgent need to urinate, frequently. It currently affects over 33 million men and women here in the US alone.
When Botox is injected into the bladder muscle, it causes the bladder to relax, increasing the bladder’s storage capacity and reducing episodes of urinary incontinence. Injecting the bladder with Botox is performed using cystoscopy, a procedure that allows a doctor to visualize the interior of the bladder while Botox is being injected.
“Clinical studies have demonstrated Botox’s ability to significantly reduce the frequency of urinary incontinence,” said Hylton V. Joffe, M.D., director of the Division of Reproductive and Urologic Products in FDA’s Center for Drug Evaluation and Research.
He also added that Botox’s safety and effectiveness for this new indication were established in two clinical trials of 1,105 patients with symptoms of overactive bladder. Patients were randomly assigned to receive injections of 100 units of Botox (20 injections of 5 units each) or placebo.
After 12 weeks results showed that patients treated with Botox experienced urinary incontinence an average of 1.6-1.9 times less per day than patients treated with placebo. Botox-treated patients also needed to urinate on average 1.0-1.7 times less per day and expelled an average of about 30 milliliters more urine than those treated with placebo.
Common side effects reported during clinical trials included urinary tract infections, painful urination, and incomplete emptying of the bladder (urinary retention). Patients who develop urinary retention may need to use a catheter until the urinary retention resolves. Patients being treated for overactive bladder with Botox should not have a urinary tract infection and should take antibiotics before, during, and for a few days after Botox treatment to lower the chance of developing an infection from the procedure.
Note:Treatment with Botox can be repeated when the benefits from the previous treatment have decreased, but there should be at least 12 weeks between treatments. Readers should consult their urologists for more information.