A SHORT-TERM, MULTICENTER, RANDOMIZED DOUBLE-BLIND DOSE TITRATION STUDY OF THE EFFICACY AND ANTICHOLINERGIC SIDE EFFECTS OF TRANSDERMAL COMPARED TO IMMEDIATE RELEASE ORAL OXYBUTYNIN TREATMENT OF PATIENTS WITH URGE URINARY INCONTINENCE

Abstract

We compared the short-term efficacy, safety and tolerability of transdermal versus oral oxybutynin in adults with urge urinary incontinence. Volunteers with detrusor instability currently responding to oral immediate release oxybutynin were enrolled in our study. Those patients presenting with recurrence of incontinent symptoms after a 2-week washout underwent confirmatory cystometrogram with subsequent randomization to transdermal or oral treatment. Matching active and placebo medications included matrix patches applied twice weekly and capsules taken 2 or 3 times daily. Dose titration was based on anticholinergic symptoms. Outcome measures included comparison of baseline to 6 week changes in incontinence episodes on a 3 day urinary diary, a visual analog scale for efficacy and anticholinergic symptoms reported on a questionnaire. Safety monitoring included adverse events and skin tolerability of the transdermal system. A total of 76 patients were enrolled and 74 completed at least 4 weeks of treatment. Mean age in the transdermal and oral groups was 64 and 63 years, and 87% and 97% were female, respectively. Daily incontinent episodes decreased in the transdermal and oral groups (7.3 to 2.4 [66%] and 7.4 to 2.6 [72%], respectively, p = 0.39). The visual analog scale reduction in urinary leakage improved from washout in both groups (p <0.0001) with no difference between them (p = 0.9). Dry mouth occurred in significantly fewer patients in the transdermal (38%) compared with those in the oral group (94%, p <0.001). Of the patients in the transdermal group 67% noticed a reduction in dry mouth severity compared with previous oral treatment, and 90% had none or mild skin erythema. Transdermal delivery of oxybutynin resulted in comparable efficacy and a significantly improved anticholinergic side effect profile compared with oral administration in adults with urge urinary incontinence.