Described are transdermal drug delivery compositions comprising amphetamine, methods of manufacturing transdermal drug delivery compositions comprising amphetamine, and therapeutic methods using transdermal drug delivery compositions comprising amphetamine, such as may be desired for achieving central nervous system stimulation, such as for the treatment of attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD), or for the treatment of narcolepsy. In some embodiments, the compositions comprise an amount of polyurethane effective to control the presence of and/or prevent the formation of phenyl acetone in the compositions. The polyurethane may be present in a drug-containing polymer matrix or in a backing adjacent the drug-containing polymer matrix.
