For women with bladder incontinence who haven't been helped by medications or other therapies, Botox injections may help control leakage better than an implanted nerve stimulation device, a new study suggests.
However, both treatments are effective, according to doctors who treat the condition.
In a head-to-head comparison, women given Botox saw their number of daily urgency incontinent episodes decrease by four, on average, compared to three for women who received the implant, called InterStim.
Botox patients also said they had a greater reduction in symptoms and were more satisfied with the treatment, the researchers said.
"Many women suffer from urgency incontinence and find inadequate relief of their problem from medications or behavioural changes," said lead researcher Dr Cindy Amundsen. She's a professor of obstetrics and gynaecology at Duke University in Durham, North Carolina.
Read: Diagnosing incontinence
"Both therapies appear to be very good options for women," Amundsen said. The differences in effectiveness between Botox and InterStim were small, but statistically significant, she added.
Urgency incontinence causes a strong, sudden need to urinate, according to the US National Institutes of Health. The condition is also called overactive bladder. Urgency incontinence is common. The problem affects about 17 percent of women over 45, and 27 percent of women over 75, the study authors noted.
Urinary tract infections
Botox works by relaxing the overactive bladder muscles that cause the problem. The implant does the same thing by sending electrical pulses to nerves in the spine, the study authors explained.
Among women who kept track of their incontinence for at least four months, far more women who received Botox reported a 75 to 100 percent reduction in urgency incontinence symptoms compared to those using InterStim, the researchers reported.
Although Botox appeared to work better than the implant, women given Botox had a greater risk of urinary tract infections, compared to women with the implant – 35 percent versus 11 percent, respectively. Also, more Botox patients needed to use a catheter to relieve urinary retention, Amundsen said.
"These side effects didn't really influence how patients thought about Botox," she said.
The most common side effect for women given the implant was the need to remove or reinsert it. But this occurred in just three percent of the women with the implant, the study reported.
Read: Causes of incontinence
The study didn't compare the costs of these US Food and Drug Administration-approved treatments, which are covered by insurance, including Medicare. However, patients may need more than one Botox injection a year, Amundsen said.
The researchers are following the women for two more years and will have data on which treatment is the most cost-effective.
Both treatments work
The report was published in the Journal of the American Medical Association.
For the study, Amundsen and her colleagues randomly assigned nearly 400 women to an injection of Botox or InterStim. The women had to have had at least six urgency incontinent episodes over three consecutive days. The women in the study also didn't get relief from other treatments. The participants were followed for six months.
According to Dr Elizabeth Kavaler, "There are two kinds of urinary incontinence – urgency incontinence and stress incontinence. These treatments work for urgency incontinence." Kavaler is a urology specialist at Lenox Hill Hospital in New York City, and was not involved with the new study.
About 80 percent of patients have their incontinence controlled by medication, Kavaler said. "The 20 percent who don't respond to medication can either do Botox or the implant," she explained.
Read: Preventing incontinence
Opting for one treatment doesn't mean you're barred from trying the other one, Kavaler said. If the Botox doesn't work, you can switch to the InterStim or vice versa, she said.
Both treatments work, Kavaler said.
"They have different side effects and different trade-offs, and it's up to the patient and the doctor together to figure out which of those trade-offs they are willing to tolerate," she said. "Usually the discussion is about what they don't want, rather than what they do want, because both treatments are good – it's all about side effects."
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