THURSDAY, Oct. 4 (HealthDay News) -- Botulinum toxin, the anti-wrinkle treatment known as Botox, can also help women with urge incontinence reduce their leaking episodes, according to a new study.

Injecting Botox into the bladder worked as well as daily solifenacin pills, a commonly prescribed treatment for incontinence, the researchers found.

The Botox treatment is already approved by the U.S. Food and Drug Administration for urge incontinence due to known neurological injuries such as spinal cord trauma, said lead study Dr. Anthony Visco, chief of urogynecology and reconstructive pelvic surgery at Duke University Medical Center in Durham, N.C.

It is not yet approved for incontinence without a recognized cause, known as idiopathic incontinence.

Visco and his colleagues conducted what they believe is the first head-to-head comparison of medication and the botulinum toxin.

They will present their results at this week's annual meeting of the American Urogynecologic Society in Chicago. The findings also will be published online Oct. 4 in the New England Journal of Medicine.

The researchers assigned nearly 250 women, all with urge incontinence, to either take daily medication and get saline injections or to get daily placebo pills and Botox injections. The women on average were in their mid- to late-50s.

With urge incontinence, the bladder is overactive and unpredictable. Up to one in five older women in the United States is affected, Visco said.

The pill used to treat the condition, solifenacin (brand name Vesicare), works by relaxing the bladder muscle. If the initial 5-milligram dose didn't help, the researchers upped the dosage to 10 mg. If that didn't work, the women were switched to another commonly used drug, trospium XR (Sanctura).

The Botox works, Visco said, by helping relax the muscles so they are not overactive. Botox injections are done via cystoscopy, in which a lighted instrument is introduced into the bladder. The Botox is injected at 15 or 20 sites and then spread evenly over the surface of the bladder, Visco said.

For six months, the women in each group kept a three-day diary once a month, noting how many episodes of incontinence they had. At the beginning, the women had an average of five episodes per day.

After six months, the average reduction in incontinence episodes was nearly the same: 3.4 episodes in the pill group and 3.3 in the Botox group.

"They both work very well," Visco said.

However, he said, "the groups that received Botox had a two-fold higher likelihood of achieving complete resolution of their incontinence."

Twenty-seven percent of those on Botox said they had no daily episodes of leaking after six months compared with 13 percent of those taking the pills.

Both groups reported side effects. Dry mouth occurred in 46 percent of those taking the pills and 31 percent of those using Botox. Those on Botox were much more likely to get a urinary tract infection, with 33 percent of them reporting one.

Those on Botox sometimes had urinary retention and had to use a catheter.

At six months, treatments were stopped. A month later, 50 percent of the women on pills still had relief of symptoms, versus 62 percent of those who got Botox. A year later, 25 percent of those on pills and 38 percent of those on Botox still had relief.

Visco estimated that the Botox would need to be repeated every nine months or so.

Another expert who reviewed the study commented on its findings.

Botox "might be a viable option for people who have failed regular therapy," said Dr. Peter Galier, an internal medicine specialist at UCLA Medical Center in Santa Monica, Calif., and associate professor of medicine at UCLA's David Geffen School of Medicine in Los Angeles.

It is crucial, he said, to be sure the diagnosis is urge incontinence and that symptoms are not due to other problems. He would prescribe other medication first, he said, and turn to the Botox treatment if the medication did not work.

The risk of infection with the Botox injections should be considered, he said.

The price of standard medication varies, as does insurance coverage. A month's supply of low-dose Vesicare, for instance, can cost about $230.

Allergan, which makes Botox, has now asked the FDA for approval for adults with idiopathic urge incontinence for whom standard medicines don't work, said company spokeswoman Heather Katt. Allergan declined to estimate costs of the injections for urge incontinence, but Katt said many plans cover the treatment for neurogenic urge incontinence and also would be expected to do so for the new indication, if it is approved.

The U.S. National Institutes of Health funded the study. Visco has no pharmaceutical company ties to report. Some co-authors report serving as consultants for Astellas Pharma US and GlaxoSmithKline, which make Vesicare.

More information

To learn more about incontinence, visit the U.S. National Institutes of Health.