Transdermal Oxybutynin

Excerpt

The anticholinergic drug oxybutynin has been the “gold-standard” treatment of urinary urge incontinence and overactive bladder for over 30 years. The drug is an effective treatment, yet the majority of patients refuse to take the medication orally because of the bothersome dry mouth that results. Development of a controlled-release formation of oxybutynin, approved by the FDA in 1999, allowed the drug to be released directly in the lower bowel, thereby bypassing presystemic gut wall metabolism to a large extent. This, in turn, decreased the concentration of the oxybutynin metabolite, N-desethyloxybutynin (DEO), the compound responsible for dry mouth (DEO has greater affinity for receptors on the salivary gland than on the bladder). …