Preliminary evaluation of a new controlled-release oxybutynin in urinary incontinence.
OBJECTIVE
To conduct a preliminary evaluation of a new oral formulation of controlled-release (CR) oxybutynin tablet taken once-daily in patients with urinary urge incontinence.


METHODS
A single-centre, open-label, 8-week study was conducted. Patients with urodynamically-confirmed detrusor instability, micturition frequency (>/= 8 voids/day) and/or urinary incontinence (>/= 2 incontinence periods/day) were enrolled. The study duration was 8 weeks: patients received IR oxybutynin (2.5-5 mg bid) for 2 weeks, followed by a 2-week washout/baseline period to avoid carryover effects, and oral CR oxybutynin (15 mg OD) for 4 weeks. Daily void frequency, fluid intake, urinary incontinence episodes, and spontaneously reported adverse events were recorded in a daily diary for five consecutive days in each treatment period.


RESULTS
Of 12 enrolled patients, 9 patients efficacy; all patients were evaluable for safety. completed the study and were evaluable for Compared to baseline/washout, CR oxybutynin reduced UI episodes/day by 45% (p = 0.13) and micturitions/day by 15% (p = 0.07). Treatment with IR oxybutynin (mean dose: 6.7 +/- 2.5 mg/day) reduced UI episodes/day from baseline by 7% (p = 0.58) and voids/day by 6% (p = 0.29). Fluid intake remained consistent at approximately 2 litres/day during all study periods. The most common adverse event was dry mouth.


CONCLUSIONS
Based on the reductions in daily frequency of incontinence and micturition following 4-weeks treatment, CR oxybutynin (15 mg OD) was at least as effective as the patients' previous dose of IR oxybutynin (mean dose: 6.7 +/- 2.5 mg/day). These improvements were achieved without restriction of fluid intake. Initial 15 mg doses of CR oxybutynin appear to be well tolerated.
Department of Urology, University Health Network, Toronto, Ontario, Canada.
Sidney B
SB
Radomski
Brenda
B
Caley
Joseph L
JL
Reiz
Paula C
PC
Miceli
Zoltan
Z
Harsanyi
Andrew C
AC
Darke
D000368:Aged; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D008297:Male; D008333:Mandelic Acids / Q000008:administration & dosage* / Q000009:adverse effects; D018727:Muscarinic Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D010865:Pilot Projects; D014549:Urinary Incontinence / Q000188:drug therapy*
D003692:Delayed-Action Preparations; D008333:Mandelic Acids; D018727:Muscarinic Antagonists; C005419:oxybutynin