Rationale for transdermal drug administration in Alzheimer disease.

Transdermal patches are used for the treatment of various diseases including neurologic and psychiatric disorders such as Parkinson disease (PD), major depression, and attention deficit hyperactivity disorder. They are believed to offer many advantages over conventional oral therapies. By providing smoother, continuous drug delivery and steadier plasma levels, patches may reduce the incidence of side effects, thus making optimal therapeutic doses easier to attain and potentially improving treatment efficacy and compliance. Drug delivery systems such as patches that are more patient- and caregiver-friendly may enable patients to continue treatment for longer periods and to attain greater, more sustained treatment benefits. To date, approved therapies for Alzheimer disease (AD), including cholinesterase inhibitors and memantine, are orally administered. Potential advantages associated with patches provide a therapeutic rationale to offer additional benefits in AD patients. Rivastigmine is well suited to patch administration because it is a small, potent molecule that is both lipophilic and hydrophilic. A rivastigmine patch has been developed and may provide a promising new approach to dementia therapy.