The present invention provides compositions and methods for administering oxybutynin
while minimizing the incidence and or severity of adverse drug experiences associated
with oxybutynin therapy. In one aspect, these compositions and methods provide
a lower plasma concentration of oxybutynin metabolites, such as N-desethyloxybutynin,
which is presumed to be contributing at least in part to some of the adverse drug
experiences, while maintaining sufficient oxybutynin plasma concentration to benefit
a subject with oxybutynin therapy. The invention also provides isomers of oxybutynin
and its metabolites that meet these characteristics of minimized incidence and/or
severity of adverse drug experiences, and maintenance of beneficial and effective
therapy for overactive bladder. In some aspects, the composition may be presented
in the form of an unoccluded or free form topically administered gel.