Sumatriptan Iontophoretic Transdermal System: A Review of Its Use in Patients with Acute Migraine
The sumatriptan iontophoretic transdermal system (ZECUITY®) [hereafter referred to as sumatriptan TDS] is the first transdermal treatment for migraine to be approved by the US FDA. This article reviews the available pharmacologic properties of sumatriptan TDS and its clinical efficacy and tolerability for the acute treatment of adult patients with migraine with or without aura. Sumatriptan, a selective 5-hydroxy-tryptamine receptor subtype 1 (5-HT1) agonist, is presumed to exert its therapeutic effect on migraine patients by binding to the 5-HT1B/1D receptors on intracranial blood vessels and sensory nerves of the trigeminal system, resulting in cranial vessel constriction and the inhibition of the release of pro-inflammatory neuropeptides and plasma extravasation. In a well designed, phase III clinical trial, sumatriptan TDS was shown to be more effective than placebo at treating a single migraine attack, with significantly more sumatriptan TDS than placebo recipients being headache pain free and nausea free at 2 hours. These data were supported by a long-term, repeat-use study over 12 months. Additionally, sumatriptan TDS was generally well tolerated in clinical trials; the most common adverse events were application-site reactions. The sumatriptan TDS formulation avoids the gastrointestinal tract, and has a controlled, sustained delivery, allowing for patients with migraine-associated nausea and vomiting to receive treatment without the risk of inconsistent absorption or avoidance of tablet use (associated with oral delivery of the drug in these patients). Moreover, it may offer a useful alternative to the nasal spray or subcutaneous sumatriptan formulations. However, definitive conclusions on the comparative efficacy and tolerability of sumatriptan TDS versus other sumatriptan formulations or other migraine drugs are not as yet possible, and data from comparative trials would be of great interest. Sumatriptan TDS is a useful addition to the treatment options available to migraine patients.