BERKELEY, CA (UroToday Inc.) - Hann-Chorng Kuo studied the use of suburothelial injection of Botulinum A toxin in 8 women and 2 men with interstitial cystitis who had failed conventional treatment. Botulinum toxin, 100 units, was injected suburothelially into 20 sites in 5 of the patients, and an additional 100 units was injected into the trigone in the other 5 patients. In 2 patients bladder pain and urinary frequency were improved 3 months after treatment. Mild difficulty in urination was reported by 7 patients. Functional bladder capacity recorded in a voiding diary was significantly increased (155 +/- 26.3 vs. 77 +/- 27.2ml) and the frequency of daily urinations (18+-7.7 vs. 24.2 +/- 10.3) and the pain score (2.4 +/-1.6 vs. 3.2 +/-1.1) were mildly but significantly reduced after treatment. Cystometric capacity improved significantly to 287 +/- 115 vs. 210 +/- 63.8ml. Trigonal injection had no therapeutic effect on symptom or urodynamic improvement.

The authors conclude that the clinical result of Botox injection was disappointing. None of the patients was symptom free and only a limited improvement in bladder capacity and pain score was achieved in 2 of 10 patients 3 months after treatment. This is a very small study, but it would seem prudent to restrict the use of botulinum A toxin to clinical research protocols until enough data is available to confirm safety and efficacy with a dose and technique that balances risk and benefit in favor of the patient.

Urol Int. 2005;75(2):170-4