July 22, 2002 -- A new drug looks promising for treatment of stress urinary incontinence, an embarrassing problem for many women. Though the drug duloxetine is still being tested and has not received FDA approval, it seems to provide many women with another option.
Stress urinary incontinence is said to affect one in three American women. It is an involuntary leakage of urine brought on by "stress" or pressure on the bladder. A woman laughs, coughs, sneezes, exercises, lifts something, and there is leakage.
In early studies, duloxetine has significantly reduced the number of episodes -- and improved the quality of life -- for women with this condition.
"There are surgical options, exercise options, but they just don't work for an awful lot of women," Richard Bump, MD, medical advisor for the duloxetine team at Eli Lilly and Company, tells WebMD. His report on the findings appears in the July issue of the American Journal of Obstetrics and Gynecology.
Indeed, behavioral therapy and exercise work in many cases, according to another study in AJOG. In that study, 31% of women who did Kegel exercises (to strengthen the muscles that support the bladder) -- and who established a voiding schedule that best suited their lifestyles -- had a 100% improvement (stayed dry) in their condition; 41% were at least 75% improved, and 52% were at least 50% improved, reports lead author Leslee L. Subak, MD, a researcher at the University of California in San Francisco.
"Clearly, behavioral therapy has a role," says Bump. "However, many women simply don't remember to do the exercises, or their lives are too busy. And some women frankly can't contract those muscles. For women who find it doesn't fit their lifestyle or ability, what we're seeing with duloxetine is that it's the first option for stress incontinence in a medication."
Though doctors have prescribed the antidepressant imipramine and the over-the-counter antihistamine Sudafed for treatment of stress incontinence, there are some negative side effects such as constricting or narrowing blood vessels, a phenomenon that can increase heart rate and blood pressure And these drugs haven't been widely studied and are not recommended for treating stress incontinence.
"[With duloxetine] we really for the first time have something that gives them an option for treatment other than wearing pads and living with their problem," says Bump.
Duloxetine is a type of drug known as a selective reuptake inhibitor; over the last few years, these drugs have been very successful in treating various conditions -- such as depression -- by increasing levels of serotonin and other brain chemicals.
Duloxetine increases the amount of serotonin and norepinephrine, another brain chemical, and seems to stimulate the muscles at the opening of the bladder, helping them contract more effectively. Thus, researchers say, accidental urine leakage is controlled.
The clinical trials were conducted at 48 centers across the U.S., involving 535 women between 18 and 65 years old. All women were having at least four episodes a week for at least three months.
Women taking 40 mg of duloxetine twice a day had significant effects -- a 64% to 100% reduction in frequency of incontinence episodes. Also, a subset of 163 women who had more severe incontinence -- at least 14 episodes per week -- also had significant decrease of symptoms.
In a quality-of-life survey, 44% of women reported feeling "very much better" or "much better," compared with 27% of those taking the placebo.
Niall Galloway, MD, medical director of the Emory Continence Center at Emory University School of Medicine in Atlanta, agreed to review the study for WebMD. He offers a bit more background on duloxetine.
"Actually, duloxetine was being studied for another use -- as a treatment for depression," says "But when women began reporting that their leakage problems were improved, a second study to investigate that finding was launched," Galloway says.
Bump's study is "quite good," he tells WebMD. "There does seem to be a big difference in terms of benefit between the two groups. Also, what's always encouraging -- as the dose increases, the benefits increase. That would imply that the medication truly is the factor here."
However, exactly how duloxetine affects bladder action isn't quite clear, says Galloway. "We always want to know what the mechanism of action is, and that is not at all clear."
Also, a medication often produces an effect in the short term -- for just a few weeks, as in Bump's study. "But when taken for a prolonged interval, it's not clear whether the physiological effects on incontinence would be sustained," Galloway says.
Another issue: Will patients want to take an antidepressant for a bladder problem? Possibly not, says Galloway. "Patients want a treatment that corrects the problem; they don't want a medication that's going to have an affect on their emotional state."
If indeed the drug is effective, then similar medications could also accomplish the same thing, Galloway says.
The duloxetine study is supported by Eli Lilly and Company, a WebMD sponsor.