New tacks in botulinum toxin show promise in interstitial cystitis

The other twists on botulinum toxin treatment were injection into the trigone only and submucosal injection in combination with hydrodistention.

In the department of urology at Hospital de São João, Portugal, Rui Pinto, MD, injects 100 U, not 200 U as other clinicians have reported doing. Further, Dr. Pinto injects the agent submucosally into the trigone only. This approach is minimally invasive, but technically a little more difficult than distributing injections across the bladder wall.

Retreatment at 6 months suggested

In this study, with the patient under general anesthesia, Dr. Pinto made 10 injections of botulinum toxin, each with 10 U in 1 mL of solution, and using a 70% angle lens through a rigid cystoscope to distribute the injections evenly across the trigone. For the 17 patients (16 women and one man) with refractory IC who underwent the therapy, pain, frequency, symptom, and problem scores all fell, and bladder capacity rose significantly, the authors reported.

Pain scores dropped from a mean of 5.7 on a 10-point scale to 2.2 at 1 month and 1.9 at 3 months. Frequency decreased from 17 times per day to 8 at 1 month and 10 at 3 months. O'Leary-Sant Symptom and Problem Index scores dropped from 15.3 to 9 at 1 month and 3.2 at 3 months. Maximum cystometric capacity increased from 38 mL to 268 mL at 1 month and then to 326 at 3 months.

At 6 months, three patients requested retreatment, and at 9 months, another four did so. "At 6 months, the patients probably should be treated again," Dr. Pinto said.

No complications were reported, and Dr. Pinto concluded, "Botulinum toxin A injected in the bladder trigone could be an effective treatment and also safe in patients with refractory interstitial cystitis."