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Antimuscarinic effects on current perception threshold: A prospective placebo control study§


  • Linda Brubaker led the review process.

  • Conflict of interest: GV, GAD, AD and RF have received grants from Pfizer Pharmaceutical Ltd. UK is a consultant and honorary speaker for Pfizer and received travel and research grants from Pfizer Pharmaceutical Ltd.

  • §

    G. Vijaya—Data collection, conception and design of study, writing the manuscript; G.A. Digesu—Data collection, conception and design of study, writing and editing the manuscript; C. Hendricken—Data collection; A. Derpapas—Editing the manuscript; R. Fernando—Design of the study and editing the manuscript; V. Khullar—Conception and design of study, editing the manuscript.



To evaluate the effect of Tolterodine on urethral and bladder afferent nerves in women with detrusor overactivity (DO) in comparison to placebo, by studying the changes in the current perception threshold (CPT).


Women with overactive bladder symptoms and idiopathic DO were recruited and randomized in a double-blind manner between placebo and tolterodine extended release. All women underwent CPT testing of the bladder and urethra using a Neurometer constant current stimulator. CPT values were determined at three frequencies, including 2,000 Hz (corresponding to Aβ-fibers), 250 Hz (corresponding to Aδ-fibers), and 5 Hz (corresponding to C fibers) before and 7 days on treatment. CPT values before and on treatment were compared using a Wilcoxon Signed Rank test.


Twenty women (mean age 46 years) were studied. There was no statistical difference between the two groups in terms of age, ethnicity, severity of symptoms and pre-treatment CPT values. Only in the tolterodine group there was a significantly increased CPT value at 5 and 250 Hz upon both urethral and bladder stimulation after 1 week of treatment. When compared with placebo, women taking tolterodine had significantly increased Bladder CPT values at 5 Hz (P-value <0.05). The electrical stimulation with 5 Hz was described as urgency.


This is a randomized placebo control study evaluating the effect of antimuscarinics on sensory nerve function in women with DO. Our results support the animal studies that antimuscarinics have an effect on sensory function. Neurourol. Urodynam. 31:75–79, 2012. © 2011 Wiley Periodicals, Inc.