Headache is a common presenting complaint to the emergency department accounting for 1-2% of patient visits. Of these headaches, approximately 90% are migraine, tension headache, or combined presentations. The most commonly used migraine therapy in the ED is intravenous prochlorperazine, but its administration requires close nursing observation, a bed, and the insertion of an intravenous catheter. Buccal prochlorperazine represents an alternative form of delivery that enables rapid achievement of therapeutic blood levels and may lead to symptom resolution. In a randomized, controlled, prospective study,the investigators plan to assess the efficacy of buccal versus intravenous prochlorperazine for the initial emergency department treatment of migraine headaches.