An update on the use of transdermal oxybutynin in the management of overactive bladder disorder

Abstract

Antimuscarinic medications are used to treat nonneurogenic overactive bladder refractory to nonpharmacologic therapy. Side effects such as dry mouth, constipation, blurred vision, dizziness, and impaired cognition limit the tolerability of therapy and are largely responsible for high discontinuation rates. Oxybutynin is a potent muscarinic receptor antagonist whose primary metabolite after first-pass hepatic metabolism is considered largely responsible for its associated anticholinergic side effects. Transdermal administration of medications bypasses hepatic processing. Specifically with oxybutynin, whose low molecular weight permits transdermal administration, bioavailability of the parent drug with oral administration is less than 10%, whereas with transdermal delivery is a minimum of 80%. The result has been an improved side effect profile in multiple clinical trials with maintained efficacy relative to placebo; however, the drug may still be discontinued by patients due to anticholinergic side effects and application site reactions. Transdermal oxybutynin is available as a patch that is changed every 3-4 days, a gel available in individual sachets, or via a metered-dose pump that is applied daily. The transdermal patch was briefly available as an over-the-counter medication for adult women, although at this time all transdermal formulations are available by prescription only.

Current pharmacotherapy of overactive bladder

“…In the Canadian study, median time to discontinuation for the different antimuscarinics varied from 75 to 108 days, with around 20% of patients persisting on medication for 12 months (37). f) Transdermal formulations: Transdermal formulations of oxybutynin have the advantage of bypassing the hepatic metabolism by CYP3A4 enzymes, hence increasing the bioavailability of oxybutynin and lowering the serum concentration of DEO, the metabolite that is mainly responsible for side effects associated with this agent (81,82). It may result in greater tolerability for the patient while maintaining efficacy (82)(83)(84).…”

Otorhinolaryngological adverse effects of urological drugs

“…Oxybutynin and tolterodine are powerful antagonists of muscle receptors (18) and have been used in the treatment of overactive bladder for over 40 years (19,20). The adverse effects of these drugs differ little from those associated with scopolamine; xerostomia, visual clouding, constipation, erythema, fatigue, sweating, dizziness, cognitive changes, sleepiness, and urinary retention have been reported in the literature (18,19,21,22). Epistaxis, characterized by the nasal--mucosa dryness as the main factor, was reported as an adverse effect of oxybutynin but was seen in one patient only (23).…”

Clinical and Economic Evaluation of Transdermal Oxybutynin in the Treatment of Overactive Bladder in Spain

“…7,8 However, transdermal oxybutynin (OXY-TDS) (Kentera ® ) shows a similar efficacy to all other muscarinic antagonists but with a better safety profile. [9][10][11] These characteristics are unique to OXY-TDS and promote greater treatment persistence, and therefore greater continence, among patients. 12 A recent meta-analysis that included 44 randomized clinical studies with 27 309 patients showed mirabegron (MI) to be as effective as muscarinic antagonists in reducing UUI and uriary frequency (except solifenacin [SO] 10 mg, which showed greater efficacy).…”

“…12 A recent meta-analysis that included 44 randomized clinical studies with 27 309 patients showed mirabegron (MI) to be as effective as muscarinic antagonists in reducing UUI and uriary frequency (except solifenacin [SO] 10 mg, which showed greater efficacy). 13 However, this study excluded OXY-TDS without further explanation, [9][10][11] although the bibliographical reference was included in the review. Due to the OXY-TDS persistence 12 and the importance in the Spanish market, 14 we believe in the need of a comparison with all pharmacological OAB treatments.…”