Oxytrol (oxybutynin transdermal system)
The following drug information is obtained from various newswires, published
medical journal articles, and medical conference presentations.
Oxytrol (oxybutynin transdermal system), is a transdermal patch
designed to deliver oxybutynin continuously and consistently over a
3- to 4-day interval after application to intact skin. Oxytrol is
available as a 39 cm2 patch system containing 36 mg of oxybutynin.
Oxytrol is indicated for the treatment of overactive bladder with
symptoms of urge urinary incontinence, urgency, and frequency.
The dose of Oxytrol is one 3.9 mg/day system applied twice
weekly (every 3 to 4 days).
FDA approval of Oxytrol was based on the efficacy and safety
evaluated in patients with urge/urinary incontinence in two phase
III controlled studies and one open-label extension study.
Study 1 was a randomized, double blind, placebo-controlled
study, comparing the safety and efficacy of Oxytrol at dose levels
of 1.3, 2.6, and 3.9 mg/day to placebo in 520 subjects. Results
showed that subjects experienced a significant reduction in weekly
incontinence episodes, urinary frequency, and urinary void volume
in active treatment groups versus placebo. An open-label, dose
titration treatment extension allowed continued treatment for up to
an additional 40 weeks for patients completing the double-blind
period. All subjects had urge or mixed incontinence with
incontinence episodes of at least 10 per week, and at least 8
micturitions per day.
Study 2 was a randomized, double blind, double-dummy trial
comparing the safety and efficacy of Oxytrol 3.9 mg/day versus
active and placebo controls in 361 subjects. All subjects had urge
or mixed incontinence and had achieved a beneficial response from
the anticholinergic treatment they were using at the time of study
entry. Results showed a significant reduction in daily incontinence
episodes, urinary frequency, and urinary void volume between
placebo and active treatment groups.
Adverse events associated with the use of Oxytrol may include
(but are not limited to) the following:
- Dry mouth
- Abdominal pain
- Application site pruritus
- Application site erythema
- Application site vesicles
Mechanism of Action
Oxybutynin is an antispasmodic, anticholinergic agent. The
active ingredient is dissolved in the thin layer of adhesive that
sticks the patch to the skin. Oxytrol delivers the medicine slowly
and constantly through the skin and into the bloodstream for the 3
or 4 days that the patch is worn. Oxytrol's transdermal
delivery system delivers 3.9 mg per day of oxybutynin consistently
and continuously through the skin into the bloodstream, bypassing
initial metabolism in the liver and the gastrointestinal tract that
occurs with oral medications, providing relief of overactive
bladder symptoms for up to four days.
Patients who have urinary retention, gastric retention,
uncontrolled narrow-angle glaucoma or hypersensitivity to
oxybutynin or other components of Oxytrol should not use
Birns J, Lukkari E, Malone-Lee JG et al. A
randomized controlled trial comparing the efficacy of
controlled-release oxybutynin tablets (10 mg once daily) with
conventiona oxybutynin tablets (5 mg twice daily) in patients whose
symptoms were stabilized on 5 mg twice daily oxybutynin. BJU
Khoury JM. Urinary incontinence. No need to be
wet and upset. NCMJ 2001 Mar/April;62(2):74-77.
Harvey MA, Baker K, Wells GA. Tolterodine
versus oxybutynin in the treatment of urge urinary incontinence: a
meta-analysis. Am J Obstet Gynecol 2001;185(1):56-61.
Cannon TW, Chancellor MB. Pharmacotherapy of
the overactive bladder and advances in drug delivery. Clin
Obstet Gynecol 2002 Mar;45(1):205-217.