Botox Approved to Treat Overactive Bladder

January 18, 2013

The US Food and Drug Administration (FDA) today approved the multipurpose drug onabotulinumtoxinA (Botox, Allergan) for yet another indication — the treatment of overactive bladder to reduce urinary incontinence.

The indication is limited to patients who cannot use or do not adequately respond to anticholinergics to treat the condition.

An injection of onabotulinumtoxinA into the bladder muscle causes it to relax, increasing the organ's storage capacity.

"Clinical studies have demonstrated Botox's ability to significantly reduce the frequency of urinary incontinence," said Hylton Joffe, MD, director of the Division of Reproductive and Urologic Products in the FDA's Center for Drug Evaluation and Research, in a press release. "Today's approval provides an important additional treatment option for patients with overactive bladder, a condition that affects an estimated 33 million men and women in the United States."

The agency determined that onabotulinumtoxinA was safe and effective for this indication on the basis of 2 clinical trials involving 1105 patients with symptoms of overactive bladder. They were randomly assigned to receive injections of 100 units of onabotulinumtoxinA or a placebo.

After 12 weeks, patients treated with onabotulinumtoxinA experienced urinary continence an average of 1.6 to 1.9 times less per day than patients receiving the placebo. They also needed to urinate 1.0 to 1.7 times less per day and expelled on average 30 mL more urine than patients treated with the placebo.

The FDA stated that onabotulinumtoxinA treatments can be repeated, but not more frequently than every 12 weeks.

Urinary tract infections, painful urination, and urinary retention were common adverse reactions observed in the clinical trials. To reduce the risk for urinary tract infections, patients should take antibiotics before, during, and a few days after onabotulinumtoxinA treatment.

The FDA approval of onabotulinumtoxinA for overactive bladder comes on top of other approved uses, which include:

More information on today's announcement is available on the FDA Web site.