**3. Botulinum Neurotoxin (BoNT)**

BoNT is a potent toxin isolated from *Clostridium botulinum*, which can cleave SNAP-25 and block the release of some neurotransmitters (e.g., acetylcholine) from pre-junctional nerves at the neuromuscular junction. This toxin has been widely used to treat muscle dysfunction, such as strabismus [10]. In urology, more and more studies have focused on the application of BoNTs in detrusor sphincter dyssynergia (DSD) [11,12], overactive bladder (OAB) [13,14], interstitial cystitis/bladder pain syndromes [15,16], benign prostatic hyperplasia (BPH) [17–20], and CP/CPPS [14,16,21] over the past decade. Growing evidence suggests that inhibition of exocytotic machinery by BoNT-A could modulate sensory processing, inflammation and glandular function [22–26]. To date, BoNT-A have been listed as a third-line treatment for refractory OAB [27] and fourth-line for interstitial cystitis/bladder pain syndromes [28] in the American Urology Association (AUA) guidelines. However, the application of BoNT-A for patients with prostate disorders is still under off-label use. In this article, we reviewed published literature documenting mechanisms of action, basic research and the clinical use of botulinum toxin in CP/CPPS from Pubmed and used botulinum toxin, chronic prostatitis, and chronic pelvic pain as search terms. In addition to published studies, we also gathered some abstracts presented at international meetings.
