Repeat botulinum injections show efficacy in interstitial cystitis

October 1, 2011

Repeat injections of onabotulinumtoxinA (Botox) over the long term are showing value in patients with interstitial cystitis.

Washington-OnabotulinumtoxinA (Botox) injected into the bladder has been a promising treatment for interstitial cystitis, but one plagued by the problem of retention. At the 2009 AUA annual meeting, low doses and trigone-only injection showed potential for effectiveness with no retention. Now, repeat injections over the long term are showing value in these patients.

At this year's AUA annual meeting in Washington, Rui Pinto, MD, a physician at Hospital de São João, São João, Portugal, reported on repeat injections in patients with refractory bladder pain syndrome/IC over the course of 5 years.

With the patient under general anesthesia, Dr. Pinto injected onabotulinumtoxinA, 100 U, through a rigid cystoscope into 10 sites from the trigone to the bladder neck (10 U per site in 1 mL of saline). (OnabotulinumtoxinA, which was recently granted FDA approval for the treatment of urinary incontinence due to detrusor overactivity associated with a neurologic condition, is not FDA approved for treatment of bladder pain syndrome/IC.) Patients received ciprofloxacin (Cipro, Proquin XR), 500 mg, 12 hours before and 2 days after injection.

Improvements in pain, nocturia seen

The changes were significant and similar after each treatment.

"The main improvements were in pain and nocturia," Dr. Pinto noted.

Pain scores dropped from between 5 and 6 to between 2 and 3 each time. Urinary frequency, which was generally 15 to 16 times a day before treatment, dropped to about 10. O'Leary-Sant scores of about 25 to 29 dropped to the 15 to 16 range. Quality of life scores of 5 to 6 improved to about 2.

"Patients related that the main improvement in frequency was nocturia," noted Dr. Pinto.

The most notable adverse event was urinary tract infection, of which there were five, mainly with Escherichiacoli. There were no cases of voiding dysfunction, including retention.

"We can conclude that intratrigonal injection of 100 U onabotulinumtoxinA is a safe, effective, and reproducible treatment for refractory PBS/IC," Dr. Pinto said.

Co-author Francisco Cruz, MD is a consultant for Allergan.