Resiniferatoxin in the treatment of interstitial cystitis: a systematic review

Resiniferatoxin, a treatment based on a physiopathological concept (the involvement of C fibers and transient receptor potential vanilloid 1 in the transmission of pain) is undergoing evaluation for interstitial cystitis. We evaluated the current evidence from relevant studies identified in PubMed and Scopus databases. Six studies provided contradictory results regarding the effectiveness of resiniferatoxin treatment. The largest study showed no improvement of overall symptoms following a single administration of resiniferatoxin. Three other articles that studied the effectiveness of a single dose of resiniferatoxin gave contradictory results. However, the other two studies, those that examined the effect of multiple or prolonged administration schemes, gave more encouraging results. The use of the regimen is generally well tolerated although mild adverse events such as increase of bladder pain during instillation were sometimes reported by patients and serious adverse events rarely occur. In conclusion, the effectiveness of resiniferatoxin in the treatment of interstitial cystitis remains unknown.