Using Botulinum Toxin A for Treatment of Interstitial Cystitis/Bladder Pain Syndrome—Possible Pathomechanisms and Practical Issues

Abstract

Treatment for patients with interstitial cystitis/bladder pain syndrome (IC/BPS) is always challenging for urologists. The main mechanism of the botulinum toxin A (BoNT-A) is inhibition of muscle contraction, but the indirect sensory modulation and anti-inflammatory effect in the bladder also play important roles in treating patients with IC/BPS. Although current guidelines consider BoNT-A injection to be a standard treatment, some practical issues remain debatable. Most clinical evidence of this treatment comes from retrospective uncontrolled studies, and only two randomized placebo-control studies with limited patient numbers have been published. Although 100 U BoNT-A is effective for most patients with IC/BPS, the potential efficacy of 200 U BoNT-A has not been evaluated. Both trigone and diffuse body BoNT-A injections are effective and safe for IC/BPS, although comparison studies are lacking. For IC/BPS patients with Hunner’s lesion, the efficacy of BoNT-A injection remains controversial. Most patients with IC/BPS experience symptomatic relapse at six to nine months after a BoNT-A injection, although repeated injections exhibit a persistent therapeutic effect in long-term follow-up. Further randomized placebo-controlled studies with a larger number of patients are needed to support BoNT-A as standard treatment for patients with IC/BPS.

Low-Energy Shock Wave Plus Intravesical Instillation of Botulinum Toxin A for Interstitial Cystitis/Bladder Pain Syndrome: Pathophysiology and Preliminary Result of a Novel Minimally Invasive Treatment

“…Intravesical hyaluronic acid or other surface protectant instillations provide barrier protection, prevent the urine solutes from continuously stimulating the afferent nerves, and allow for the resolution of suburethelial inflammation [ 102 ]. Intravesical BoNT-A injections have strong anti-inflammatory effects in both the suburothelium and central nervous system [ 103 ]. LESW initiates new inflammation that overrides the unresolved old bladder inflammation, improves bladder perfusion, and promotes tissue regeneration [ 75 , 76 ].…”

Botulinum Toxin A Injection for Autonomic Dysreflexia—Detrusor Injection or Urethral Sphincter Injection?

“…In addition to motor inhibition, Botox also has effects on the sensory neurons. The application of a sensory blockade has been proven effective in patients with bladder pain syndrome treated with intravesical injections [ 24 ]. These mechanisms include a decrease in both the release of neurotransmitters and the expression of nociceptors, as well as the suppression of afferent nerve sprouting and reorganization [ 25 ].…”

Therapeutic approaches for UCPPS management: research advances, experimental targets, and future directions

“…A recent animal study showed that after intra-detrusor injections of BoTN-A, there was a retrograde transport of BoTN-A to the lumbosacral sensory ganglia, followed by further transmission to the spinal cord (Papagiannopoulou et al, 2016). However, evidence of therapeutic efficacy in epidemiological clinical studies has been inconsistent, raising concerns about BoTN-A's long-term effectiveness (Jhang, 2019). Due to the risk of therapeutic escape (Maignel et al, 2022), inconsistent outcomes, and practical concerns regarding BoTN-A injections, this is currently a fourth-line treatment option for UCPPS patients (Fig.…”