Purpose: We evaluated the efficacy, patient acceptability and side effect profile of tolterodine, a new antimuscarinic agent for treating bladder overactivity.
Materials and methods: In our randomized, placebo controlled, parallel group study 123, 129 and 64 patients 18 years old or older with proved detrusor overactivity (idiopathic detrusor instability or detrusor hyperreflexia) were randomized to receive 1 or 2 mg. tolterodine, or placebo, respectively, twice daily for 12 weeks. Main outcome measures were number of voids per 24 hours, urine volume per void and episodes of urge incontinence per 24 hours on a frequency-volume chart with detailed recording of side effects.
Results: After 12 weeks of treatment mean number of voids per 24 hours plus or minus standard deviation decreased from 11.2 +/- 3.1 to 9.0 +/- 2.6 with the 2 mg. dosage (p = 0.0045 versus placebo). At this dose mean urine volume per void increased from 155 +/- 52 to 190 +/- 70 ml. (p <0.0001 versus placebo), while mean number of incontinence episodes per 24 hours decreased from 3.6 +/- 4.0 to 1.8 +/- 3.1 (p = 0.19 versus placebo). Similar efficacy was observed in patients receiving the 1 mg. dose. Severe dry mouth was reported by only 2, 1 and 2% of patients given the 1 and 2 mg. dose, and placebo, respectively. There was no clinical or electrocardiographic evidence of significant cardiac adverse events.
Conclusions: Tolterodine administration resulted in a significant decrease in the frequency of voiding and improved voided volume but it was seldom associated with troublesome or severe side effects.