Study Compares Women’s Incontinence Treatments

A new study comparing treatments for a type of urinary incontinence in women found that each has benefits and drawbacks.

Millions of women experience urinary incontinence, the involuntary loss of urine. Pregnancy and childbirth, menopause and the structure of the female urinary tract make women twice as likely as men to have the condition. Different types of urinary incontinence require different treatments.

Urge urinary incontinence is the unpredictable release of urine shortly after feeling an urge to urinate. It results from unpredictable activity of the bladder muscles. The cause is often unknown. Medicines called anticholinergics can help relax bladder muscles and prevent bladder spasms. However, many women who take these medications have unpleasant side effects.

In August 2011, the U.S. Food and Drug Administration approved Botox, or onabotulinumtoxinA, for treating urge urinary incontinence in people with nervous system disorders such as spinal cord injury and multiple sclerosis. Botox injections work by relaxing overactive muscles. The drug is currently not FDA-approved to treat an overactive bladder without a neurologic cause.

A team of researchers set out to compare treatments for women with urge urinary incontinence but no neurologic disease. Led by Dr. Anthony G. Visco of Duke University Medical Center and Dr. Susan F. Meikle of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the team studied nearly 250 women, who had an average age of 58 years.

Participants were randomly put into 2 groups. One received Botox injections in the bladder muscle and placebo pills for 6 months. The other received a saline injection in the bladder muscle and took oral anticholinergic medication for 6 months. The study, which was funded by NICHD and the NIH Office of Research on Women's Health, appeared on October 4, 2012, in the online edition of the New England Journal of Medicine.

About 90% of the women in each group responded to treatment within a month. At the end of 6 months, about 70% of the women in each group reported that their symptoms were adequately controlled. After 6 months, the average number of daily episodes had declined from about 5 per day to about 1-2 per day. Urinary leakage did not return at all in about 27% of women receiving Botox and 13% of those taking oral medication.

Though the women stopped taking the pills after 6 months, 52% who had received Botox reported adequate symptom control 9 months after the start of treatment, compared with 32% in the oral medication group. At 12 months, the figures were 38% and 25%. Women in the Botox group, however, were more likely to experience incomplete bladder emptying and urinary tract infections. The women taking the oral medication were a little more likely to report dry mouth.

“Previously, Botox was reserved for women who had tried oral medications but found them ineffective,” Meikle says. “Because we included some women who had not been treated with oral medication before, these results suggest that Botox could be discussed as an option for first line treatment.” Ongoing studies are now evaluating the cost-effectiveness of the 2 approaches.