Brachial Artery Vasospasm From Sequential Use of Intravenous Promethazine and Dihydroergotamine for Treatment of Status Migrainosus: A Case Report.

Promethazine, a common antiemetic, can cause severe tissue injury with intravenous (IV) injection. Dihydroergotamine (DHE), commonly used for the acute treatment of migraine, can cause arterial vasoconstriction. We report a rare complication of brachial artery vasospasm in a patient receiving IV promethazine and DHE sequentially through the same midline IV catheter. A 40-year-old woman with history of migraine headaches and Raynaud phenomenon was admitted for treatment of status migrainosus with scheduled IV DHE infusions. While receiving the DHE infusions, IV promethazine was added to the patient's regimen to treat nausea. During an infusion of DHE, the patient developed acute pain near the catheter insertion site due to active extravasation of IV DHE. An arterial Doppler ultrasound demonstrated stenosis in the right brachial artery near the region of infusion. The patient ultimately required balloon angioplasty and intra-arterial injection of nitroglycerin to restore adequate blood flow. We hypothesize that caustic injury to the right brachial vein from IV promethazine predisposed the patient to the extravasation of DHE, which, in turn, caused adjacent brachial artery vasospasm. This case suggests the need for careful consideration, if not strict avoidance, of the use of concurrent IV promethazine and DHE.