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.
Radomski
Sidney B
SB
Department of Urology, University Health Network, Toronto, Ontario, Canada.
Caley
Brenda
B
Reiz
Joseph L
JL
Miceli
Paula C
PC
Harsanyi
Zoltan
Z
Darke
Andrew C
AC
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