Once daily controlled versus immediate release oxybutynin chloride for urge urinary incontinence. OROS Oxybutynin Study Group

J Urol. 1999 Jun;161(6):1809-12.


Purpose: We compared the efficacy and safety of once daily controlled and immediate release oxybutynin for incontinence.

Materials and methods: This multicenter, randomized, double-blind, active control, parallel study was designed to evaluate urge urinary incontinence episodes using a 7-day diary.

Results: A total of 97 women and 8 men 34 to 76 years old with urge incontinence or mixed incontinence with a clinically significant urge component were enrolled in the study. The number of weekly urge incontinence episodes decreased from 27.4 to 4.8 after controlled and from 23.4 to 3.1 after immediate release oxybutynin (p = 0.56), and total incontinence episodes decreased from 29.3 to 6 and from 26.3 to 3.8, respectively (p = 0.6). Weekly urge incontinence episodes from baseline to end of study also decreased to 84% after controlled and 88% after immediate release oxybutynin (p = 0.7). Continence was achieved in 41% of the controlled and 40% of the immediate release group (p = 0.9). Dry mouth of any severity was reported by 68 and 87% of the controlled and immediate release groups, respectively (p = 0.04), and moderate or severe dry mouth occurred in 25 and 46%, respectively (p = 0.03).

Conclusions: Participants taking a single daily does of controlled release oxybutynin had similar reductions in urge incontinence and total incontinence episodes compared to those taking oxybutynin 1 to 4 times daily. A lower incidence of dry mouth was reported for controlled release oxybutynin.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Cholinergic Antagonists / administration & dosage*
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Mandelic Acids / administration & dosage*
  • Middle Aged
  • Urinary Incontinence / drug therapy*


  • Cholinergic Antagonists
  • Mandelic Acids
  • oxybutynin