Study shows Botox safe, effective for urinary incontinence treatment

By Robin Russell

Clinical studies conducted at UT Southwestern in 2010 have spurred the recent Food and Drug Administration approval of using Botox to treat patients with urinary incontinence as a result of neurological conditions.

This novel use of the neurotoxin product, routinely used in cosmetic surgery procedures, will help patients with spinal cord injury and multiple sclerosis, said Dr. Gary Lemack, Professor of Urology and of Neurology and Neurotherapeutics, and principal investigator for the study.

Dr. Gary Lemack
Dr. Gary Lemack

“This will have profound significance in improving the quality of life of patients with neurogenic overactive bladder conditions – those who commonly have debilitating incontinence conditions related to their underlying neurological disorder,” Dr. Lemack said.

Urinary incontinence may arise from spinal cord injuries that can disrupt the normal control of bladder contractions, or from MS, a disease that results in plaques in the central nervous system that can alter normal communication between the brain, spinal cord and bladder. Medical experts report that about 340,000 people in the U.S. with MS or spinal cord injury are affected by urinary incontinence.

Standard treatments for overactive bladder conditions include the use of medications known as anticholinergics, which relax the bladder musculature. UT Southwestern researchers who participated in multicenter clinical trials last year, however, showed that Botox can be used safely and effectively in the treatment of urinary incontinence caused by overactivity of the detrusor, the muscle that helps empty the bladder, particularly when anticholinergics are ineffective or poorly tolerated.

Almost 700 patients in the trials were randomized to receive a physician-administered treatment of either 200 units or 300 units of Botox or placebo injected across the bladder muscle in an office-based procedure.

The Botox injections temporarily alter muscle contractions by blocking the transmission of nerve impulses to the bladder muscle. Recent data suggest that Botox may also alter perception of bladder fullness, another mechanism by which it might help treat overactive bladder conditions.

Findings of the clinical trials demonstrated significant reductions within two weeks in the frequency of incontinence episodes in patients treated with the Botox compared to those given a placebo, and about 20 fewer episodes per week by the sixth week. The results of the Botox treatment lasted up to 10 months.

The most common adverse reactions were urinary tract infection in 24 percent of the patients, and urinary retention in 17 percent. Those who develop urinary retention after Botox treatment may require self-catheterization temporarily to empty the bladder, researchers said. Patients enrolled in the clinical trials were then placed in a long-term follow-up study, which is still ongoing.

Botox is marketed in the U.S. by Allergan Inc., an Irvine, Calif.-based firm that funded the clinical trials.

Dr. Lemack holds the Rose Mary Haggar Professorship in Urology.