Equal pain relief across interstitial cystitis phenotypes with botulinum

Milan, Italy-Trigonal onabotulinumtoxinA (Botox) brings equal analgesic relief to patients with ulcerative and non-ulcerative forms of bladder pain syndrome/interstitial cystitis (BPS/IC) alike, according to the results of a recent study.

The study outcomes suggest that the bladder pain experienced in this syndrome is not directly related to the ulcers themselves, which challenges the traditional view that ulcerative BPS/IC patients should be directly treated with fulguration or laser treatments of Hunner’s lesions. The study authors found no differences between the two phenotypes.

First author Rui Miguel Correia de Almeida Pinto, MD, urologist at São João Hospital, Porto, Portugal, treated 24 refractive BPS/IC patients with intra-trigonal botulinum injections (100 U) in a trial designed to understand whether the ulcerative and non-ulcerative phenotypes of BPS/IC had different symptomatic outcomes or duration of effect. He also compared the levels of urinary neurotrophines and norepinephrine in response to botulinum.

“The symptomatic relief brought by onabotulinumtoxinA, namely for pain and frequency, is the same for ulcerative or non-ulcerative forms of bladder pain syndrome. In our experience, the presence of ulcers does not interfere or enhance the severity of the disease and should be treated the same as the non-ulcerative form,” Dr. Pinto said during a presentation at the European Association of Urology annual congress in Milan, Italy.

In their data analysis, the only difference the researchers found was in the duration of symptoms between the two forms of BPS/IC, he noted.

Ten patients with ulcerative and 14 patients with non-ulcerative BPS/IC were evaluated at presentation and 1 month after intra-trigonal injection of botulinum, 100 U. Each patient received 10 injections (10 U each). In addition to a 10-point visual analogue scale to quantify pain, the authors evaluated frequency and nocturia in a 3-day voiding chart, O’Leary-Sant Score, quality of life (QoL), and duration of effect. Urinary nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and norepinephrine were accessed by ELISA.

The mean patient age was 40±12 years in the ulcerative group and 47±13 years in the non-ulcerative group. Ulcerative patients were classified as 3a (n=1), 3b (n=3), and 3c (n=6) according to the International Society for the Study of BPS classification. Non-ulcerative patients were classified as 2a (n=3), 2b (n=5), and 2c (n=6). The mean values at baseline for pain, frequency, nocturia, O’Leary-Sant Score, and QoL were identical for the two groups, as were the urinary NGF, BDNF, GDNF, and norepinephrine.

Longer symptom duration in ulcerative group

Patients with the ulcerative phenotype had a longer duration of symptoms than those without ulcers (28.8±11 vs. 19.2±8 months, respectively, p=.018). The duration of effects was similar-9±2.8 months in the ulcerative group versus 10.5±2 months in the non-ulcerative group-which was statistically insignificant, Dr. Pinto observed.

The two groups responded equally to botulinum with a marked decrease in pain, frequency, nocturia, O’Leary-Sant, QoL, and in urinary neurotrophines and norepinephrine levels.

Dr. Pinto explained that ulcerative BPS/IC is traditionally viewed as more painful. Fulguration or resection of the ulcers is frequently recommended. The two forms have different histopathologic, immunologic, and neurobiologic features. However, the symptoms are similar, with chronic pain related to bladder filling and urinary frequency, and both respond equally to trigonal botulinum, he concluded.UT