Transdermal delivery of sumatriptan for the treatment of acute migraine

Migraine is a common, multisymptom disorder that can severely impact the daily activities of migraineurs. Triptans (primarily sumatriptan) are the most commonly prescribed treatment for migraine and are considered a relatively safe and effective initial therapy. Unfortunately, current sumatriptan formulations (i.e., oral, nasal, subcutaneous) may be associated with limitations that can result in patients' delaying or avoiding treatment. For oral formulations, these limitations include difficulty in taking an oral medication due to the nausea and vomiting that often accompany migraine, and inconsistent absorption, whereas nasal and subcutaneous formulations may be associated with low bioavailability and an undesirable rate of adverse events, respectively. An alternative to current formulations is transdermal drug delivery, particularly iontophoresis. Transdermal delivery has several advantages over current formulations, including avoidance of the gastrointestinal tract, controlled and sustained delivery, and convenient administration. This article reviews the in vitro, in vivo, and preclinical data supporting the use of iontophoresis for the delivery of sumatriptan, as well as the recent clinical data for Zelrix (NuPathe Inc., Conshohocken, PA), an iontophoretic sumatriptan patch currently in phase III development for the treatment of migraine.