Intranasal civamide for the acute treatment of migraine headache

The objective of this study was to investigate the safety and efficacy of i ntranasal civamide for the acute treatment of migraine headache with or wit hout aura. Civamide is a vanilloid receptor agonist and neuronal calcium ch annel blocker that inhibits the neuronal release of excitatory neurotransmi tters (e.g. calcitonin gene-related peptide (CGRP) and substance P (SP)) an d depletes the neurones of the trigeminal plexus of their neurotransmitter content. Applied intranasally, the release of neurotransmitters to meningea l and dural blood vessels should be decreased, along with the resultant vas odilatation, plasma extravasation, and histamine/serotonin release. Subsequ ent migraine headache pain may also be diminished. Thirty-four patients wer e enrolled into a double-blind study of intranasal civamide, and randomized to receive a single dose of either 20 mug or 150 mug of civamide, for the treatment of a single migraine headache, with or without aura, of moderate to severe pain. At 2 h post-dose, 55.6% of patients treated with either dos e had a decrease in pain severity, with 22.2% of patients being pain-free. At 4 h post-dose, 72.7% of patients treated with either dose had a decrease in pain severity, with 33.0% of patients being pain-free. Adverse events w ere similar for both dosages, with 91.2% of patients experiencing nasal bur ning and 44.1% of patients experiencing lacrimation. No systemic side-effec ts were observed. Based upon the results of this study, intranasal civamide may be effective in the acute treatment of migraine headache. Given civami de's proposed mechanism of action, intranasal civamide should be substantia lly more effective for prophylaxis than acute treatment of migraine. A stud y evaluating its efficacy in prophylaxis of migraine is currently planned.