Botulinum toxin A (BTX-A) is a powerful neurotoxin with long-lasting activity that blocks muscle contractions. In addition to effects on neuromuscular junctions, BTX-A also plays a role in sensory feedback loops, suggesting the potentiality for pain relief. Although the only approved indications for BTX-A in the bladder are neurogenic detrusor overactivity and refractory overactive bladder, BTX-A injections to treat bladder pain refractory to conventional therapies are also recommended. The mechanism of BTX-A activity in bladder pain is complex, with several hypotheses proposed in recent studies. Here we comprehensively reviewed properties of BTX-A in peripheral afferent and efferent nerves, the inhibition of nociceptive neurotransmitter release, the reduction of stretch-related visceral pain, and its anti-inflammatory effects on the bladder urothelium. Studies have also revealed possible effects of BTX-A in the human brain. However, further basic and clinical studies are warranted to provide solid evidence-based support in using BTX-A to treat bladder pain.
Toxins. 2020 Feb 03*** epublish ***
Ting-Chun Yeh, Po-Cheng Chen, Yann-Rong Su, Hann-Chorng Kuo
Division of Urology, Department of Surgery, Taiwan Adventist Hospital, Taipei City 105, Taiwan., Department of Urology, En Chu Kong Hospital, New Taipei City 237, Taiwan., Department of Urology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu City 300, Taiwan., Department of Urology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and Tzu Chi University, Hualien City 970, Taiwan.