The effect of cholinergic enhancement during filling cystometry: Can edrophonium chloride be used as a provocative test for overactive bladder?

Purpose: Overactive bladder, a highly prevalent disorder, is suspected of h aving a low detection rate due to the lack of sensitive diagnostic tools. R ecent studies imply the involvement of the cholinergic system in the pathop hysiological mechanism underlying overactive bladder. We determined whether in vivo enhancement of cholinergic activity with edrophonium chloride, a p otent cholinesterase inhibitor, would serve as a provocative maneuver to in crease the sensitivity of filling cystometry. Materials and Methods: A total of 27 patients underwent a multichannel vide o urodynamic evaluation, followed by filling cystometry with the intravenou s administration of 10 mg. edrophonium chloride. The response to edrophoniu m was defined as a significant change in sensation and decreased bladder ca pacity, the induction or amplification of involuntary detrusor contractions , or significantly decreased detrusor compliance. Findings were compared in responders and nonresponders. Results: We identified 11 responders and 16 nonresponders. A response was n oted in 78% of the patients with the symptomatology of overactive bladder b ut in none with no specific complaints suggesting bladder overactivity. In 7 of the 12 responders (64%) baseline cystometry was interpreted as normal, In 6 of the 11 responders (54%) uninhibited urinary leakage was observed i n response to edrophonium. There were no serious adverse reactions to the d rug. Conclusions: This preliminary study implies that edrophonium may serve as a novel, practical and safe drug far provocative cystometry. By significantl y increasing cystometry sensitivity the drug would facilitate the identific ation of the subset of patients with overactive bladder who are currently c lassified with sensory urgency.