By Alan Mozes
With the condition, an overactive bladder contracts too often or without warning, leading to the constant urge to urinate and/or bladder leakage. But two studies, slated to be presented Friday at the American Urological Association annual meeting in New Orleans, offer evidence that injecting Botox directly into the bladder muscle may be an effective and safe way to treat the problem.
"The bottom-line gist is that we found that Botox has a good, long-lasting, safe and consistent effect over time among patients who do initially respond well to it and choose to continue treatment," said Dr. Victor Nitti, vice chair of the department of urology at NYU Langone Medical Center in New York City.
Nitti, who is also director of NYU's department of female pelvic medicine and reconstructive surgery, was involved in two of three new studies of Botox.
In the first study, the only one funded by Botox maker Allergen Inc., Nitti and his colleagues analyzed data on 227 patients who received Botox injections (averaging less than two shots per year) over a four-year period.
Quality-of-life scores doubled and tripled throughout the study, the researchers found. The most frequent serious side effect was a urinary tract infection, but the research team stressed that that risk did not increase with continued treatment.
Nitti also led a second investigation that looked at how slightly more than 250 patients -- from an earlier trial -- continued to fare while receiving between one and six additional Botox injections over a three-year follow-up study.
The result: the team once again found that long-term Botox treatment produced a consistent drop in daily incontinence episodes, with one injection producing stable results for an excess of one year among a third of patients.
On the other hand, a third study slated for the meeting had results that were not that promising. The researchers looked at about 300 patients who had an initial Botox injection to treat incontinence between 2010 and 2014 to determine the treatment's impact on acute urinary retention.
All of the patients had been diagnosed with a form of incontinence for which no specific underlying cause could be identified.
That research team, led by Dr. Olufenwa Milhouse, an urologist in Woodbury, Minn., found that a fifth of the patients ultimately needed catheterization for acute urinary retention. But, the study authors added, 40 percent of patients chose to have a second Botox injection.
Overall, Dr. Michael Chancellor, director of the Aikens Neurourology Research Center at the Beaumont Health System in Royal Oak, Mich., said the message is clear: "Botox is not just for wrinkles anymore."
"I think the two large trials clearly demonstrate that [Botox] has good sustained efficacy and safety after several years of repeated injection," he said.
"Patients who suffer from overactive bladder [urinary incontinence] now have a minimally invasive treatment option, giving them the successful results they want with minimal side effects," Chancellor added.
Botox was first approved by the U.S. Food and Drug Administration to treat overactive bladder in January 2013.
Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed medical journal.