NIH Study Compares Botox and Oral Meds in Women With Urinary Incontinence
Both forms of treatment have benefits and drawbacks (Oct. 4)
Oral medications for treating a type of incontinence in women are roughly as effective as Botox injections to the bladder, according to an October 4 announcement from the National Institutes of Health (NIH).
In an NIH clinical trials network study, women in both treatment groups said that the average number of daily episodes had declined from about five per day to about one or two per day after 6 months of treatment.
In the study, researchers compared the effectiveness of Botox injections with that of oral anticholinergic medications for treating urge urinary incontinence (UUI) in women. Nearly 250 women, with an average age of 58 years, participated in the trial.
Anticholinergic medications reduce bladder contractions by targeting the bladder muscle through the nervous system. Many women who take these drugs experience adverse side effects, including constipation, dry mouth, and dry eyes.
The proportion of women receiving Botox whose urinary leakage completely went away 6 months after starting treatment (27%) was twice that of the group taking oral medications (13%).Women in the Botox group, however, were more likely to experience incomplete bladder emptying or bladder infections, while the women taking oral medications were more likely to report that they had dry mouth — a common side effect of anticholinergics.
The study findings were published online in the New England Journal of Medicine.
Women are twice as likely as men to experience urinary incontinence, and older women are more likely to experience the disorder compared with younger women. An estimated 15.7% of U.S. women experience urinary incontinence, primarily due to pregnancy and childbirth, menopause, and the structure of the female urinary tract.
UUI results from unpredictable activity of the bladder muscles, the cause of which is often unknown. Botox injections work by relaxing the overactive muscles. In August 2011, the FDA approved Botox (onabotulinumtoxinA) for the treatment of UUI when the disorder is due to spinal cord injury, multiple sclerosis, or other nervous-system disorders. OnabotulinumtoxinA is not FDA-approved to treat an overactive bladder without a neurologic cause, even when other therapies have been found to be ineffective.
In the new double-blind study, women diagnosed with UUI were divided randomly into two groups. One group received Botox injections in the bladder muscle plus placebo pills for 6 months. The other group received a saline injection in the bladder muscle and took an oral anticholinergic medication for 6 months.
About 90% of the women in each group responded to treatment within 1 month. At the end of 6 months, about 70% of the women in each group reported that their symptoms were adequately controlled. Nine months after the start of treatment, 52% of the women who had received Botox reported adequate symptom control, compared with 32% of the oral anticholinergic group. At 12 months, the corresponding figures were 38% and 25%.
In addition, the side effects in the two groups differed. Two months after the start of treatment, women in the Botox group needed to use a catheter more often to empty their bladders completely (5% vs. 0%) and were more likely to experience urinary-tract infections (33% vs. 13%). Women taking an oral anticholinergic medication were more likely to report dry mouth (46% vs. 31%).
Ongoing studies are evaluating the cost-effectiveness of the two approaches.
For more information, visit the NIH Web site.