Effect of controlled-release oxybutynin on neurogenic bladder function in spinal cord injury.
OBJECTIVE
This study evaluated the effects and tolerability of extended-release oxybutynin chloride on the frequency of voiding and catheterization and urodynamic capacity in spinal cord injury (SCI) patients with defined detrusor hyperreflexia.


METHODS
This was a 12-week, prospective, dose-titration study of extended-release oxybutynin (oxybutynin XL). SCI patients with urodynamically defined detrusor hyperreflexia were recruited for this study. Following a 7-day washout period, patients were evaluated via video-urodynamic study and then treatment was initiated at a dosage of 10 mg per day. Dosage was increased in weekly intervals to a maximum of 30 mg per day. Micturation frequency diaries and urodynamics were completed at baseline and repeated at week 12. Tolerability information was collected at each follow-up visit.


RESULTS
Ten patients (mean age = 49 years) with complete or incomplete SCI were enrolled. Participants reported clinical improvement (decreased urinary frequency and fewer incontinence episodes) with oxybutynin therapy following titration to 30 mg per day. All patients chose a final effective dosage of greater than 10 mg, with 4 patients taking the maximum of 30 mg per day. Mean cystometric bladder capacity increased from 274 mL to 380 mL (P = 0.008). No patient experienced serious adverse events during the 12-week study.


CONCLUSIONS
Oxybutynin XL is safe and effective in patients with detrusor hyperreflexia secondary to SCI. The onset of clinical efficacy occurs within 1 week, and daily dosages up to 30 mg are well tolerated.
O'Leary
Margie
M
Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
Erickson
Janet R
JR
Smith
Christopher P
CP
McDermott
Charlotte
C
Horton
John
J
Chancellor
Michael B
MB
D000328:Adult; D000368:Aged; D020211:Autonomic Dysreflexia / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D003692:Delayed-Action Preparations / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008333:Mandelic Acids / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D010276:Parasympatholytics / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D011446:Prospective Studies; D013119:Spinal Cord Injuries / Q000150:complications* / Q000188:drug therapy* / Q000503:physiopathology; D013997:Time Factors; D001750:Urinary Bladder, Neurogenic / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D014563:Urodynamics / Q000187:drug effects / Q000502:physiology
D003692:Delayed-Action Preparations; D008333:Mandelic Acids; D010276:Parasympatholytics; C005419:oxybutynin