title: Does tolterodine extended release affect the bladder electrical perception threshold? A placebo controlled, double-blind study with 4 and 8 mg in healthy volunteers.
abstract: OBJECTIVE
  We evaluated the influence of tolterodine extended release on human bladder afferents. The afferents were assessed by determining the bladder electrical perception threshold using endovesical electrical stimulation at different potentially neuroselective frequencies.
  
  
  METHODS
  A total of 30 healthy female subjects with a mean +/- SD age of 23.6 +/- 2.3 years and a mean body mass index of 20.5 +/- 1.7 kg/m2 were assigned to 3 groups of 10 each in a double-blind manner, including group 1-placebo, group 2-4 mg tolterodine extended release and group 3-8 mg tolterodine extended release. The investigation was performed using an 8Fr catheter for filling and stimulation that was placed at the bladder neck in a 100 ml filled bladder. Bipolar stimulation was performed using 2.5, 5 and 250 Hz stimuli. Subjects were asked to indicate sensation by pressing a button. Electrical perception thresholds were determined using the method of levels. Electrical perception thresholds were determined before and 4 hours after medication.
  
  
  RESULTS
  No significant change in the electrical perception threshold after treatment could be found among the groups at 2.5, 5 and 250 Hz (p = 0.178, 0.817 and 0.365, respectively). There was a tendency in the tolterodine extended release groups toward an increased electrical perception threshold at 250 Hz (4 mg less than 8 mg). In most cases electrical stimulation with 2.5 and 5 Hz was described as a slight twinge, tickle or desire to void. Stimulation with 250 Hz was the most uncomfortable one, described as a strong, distinct twinge or burning "like urinary tract infection."
  
  
  CONCLUSIONS
  Although a tendency was observed toward an increased electrical perception threshold at 250 Hz, this study showed no significant effect of tolterodine extended release on the bladder electrical perception threshold.
authors.affiliation: Neurourology Department, Spinal Cord Injury Center, Balgrist University Hospital, Zürich, Switzerland. ulrich.mehnert@paralab.balgrist.ch
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mehnert
authors.forename: André
authors.initials: A
authors.lastname: Reitz
authors.forename: Maya
authors.initials: M
authors.lastname: Ziegler
authors.forename: Peter A
authors.initials: PA
authors.lastname: Knapp
authors.forename: Brigitte
authors.initials: B
authors.lastname: Schurch
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001559:Benzhydryl Compounds / Q000008:administration & dosage*; D003408:Cresols / Q000008:administration & dosage*; D003692:Delayed-Action Preparations / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D018727:Muscarinic Antagonists / Q000008:administration & dosage*; D010665:Phenylpropanolamine / Q000008:administration & dosage*; D012016:Reference Values; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds / Q000187:drug effects*; D000068737:Tolterodine Tartrate; D001743:Urinary Bladder / Q000187:drug effects* / Q000294:innervation; D014546:Urinary Catheterization; D014563:Urodynamics / Q000502:physiology
chemical_list: D001559:Benzhydryl Compounds; D003408:Cresols; D003692:Delayed-Action Preparations; D018727:Muscarinic Antagonists; D010665:Phenylpropanolamine; D000068737:Tolterodine Tartrate