A randomized, double-blind, parallel-group comparison of controlled- and immediate-release oxybutynin chloride in urge urinary incontinence.
OBJECTIVE
The aim of this study was to evaluate the efficacy and safety of a new PO controlled-release (CR) QD oxybutynin tablet relative to PO immediate-release (IR) TID oxybutynin in patients with urge urinary incontinence (UI).


METHODS
In this multicenter, double-blind trial, patients with UI (> or = 7 episode/wk) and frequency (> or = 8 micturitions/d) were randomized to CR or IR oxybutynin for 6 weeks. Patients initiated treatment at 15 mg/d and the dose was adjusted (in 5-mg/d increments) over 2 weeks according to tolerability. Efficacy (UI episodes, voids, absorbent pads used, urgency, and volume voided per micturition) was assessed during the final 2 weeks of treatment. Tolerability was assessed by evaluating adverse events and treatment withdrawals.


RESULTS
Of the 125 patients randomized, 94 (75%) were evaluable for efficacy; tolerability was assessed in all patients. In the CR group, 48 patients (91%) were women and 5 (9%) were men; the mean (SD) age was 58.0 (12.4) years (range, 26-78 years). In the IR group, 37 patients (90%) were women and 4 (10%) were men; the mean (SD) age was 60.6 (14.8) years (range, 26-83 years). Both CR and IR oxybutynin significantly reduced the mean number of total UI episodes per week (both P < 0.001 vs baseline). Both treatments produced equivalent reductions in mean voiding frequency and urinary urgency (all P < 0.001 vs. baseline). Significantly more patients rated CR oxybutynin tolerable on the initial dose of 15 mg/d (P = 0.020) and completed the study at a dose of > or = 15 mg/d (P = 0.018). Dry mouth was the most common adverse event, reported by 68% and 72% of patients in the CR and IR oxybutynin groups, respectively.


CONCLUSIONS
Among the patients with urge UI included in this study, CR oxybutynin was as effective as IR oxybutynin for improving primary symptoms, with the additional benefit of QD administration.
Barkin
Jack
J
University of Toronto, Toronto, Ontario, Canada.
Corcos
Jacques
J
Radomski
Sidney
S
Jammal
Marie-Paule
MP
Miceli
Paula C
PC
Reiz
Joseph L
JL
Harsanyi
Zoltan
Z
Darke
Andrew C
AC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008333:Mandelic Acids / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014549:Urinary Incontinence / Q000145:classification / Q000188:drug therapy*
D003692:Delayed-Action Preparations; D008333:Mandelic Acids; C005419:oxybutynin