Objective.—This study was designed to investigate the efficacy and safety of intravenous valproate in the treatment of acute migraine attacks.
Background.—Numerous studies have shown oral valproate therapy to be effective in preventing migraine. To date, no published studies have explored the use of valproate in the acute treatment of migraine.
Design/Methods.—After obtaining written informed consent, 61 patients presenting to a clinic with acute migraine were infused with 300 mg of intravenous valproate sodium. Sixty-six attacks were treated. The time at the beginning of infusion; the time at the end of infusion; the time to onset of relief of headache, nausea, and other associated symptoms; the time to meaningful relief; and the time to complete relief were recorded. Patient's pulse, blood pressure, and respiration were monitored. Adverse events were recorded.
Results.—Mean time to onset of relief was 8 minutes, mean time to meaningful relief was 16 minutes, and mean time to complete relief was 25 minutes. A reduction in pain from severe or moderate to mild or no pain in 30 minutes was reported in 37 of 66 attacks; in 11 attacks, a reduction of more than 50% in headache severity in 30 minutes was reported. Thus, 48 (73%) of 66 attacks had significant improvement. After treatment with valproate, headache severity was significantly decreased (P<.0001); nausea, disability, and photophobia decreased; and patients became more alert. No serious adverse events were reported.
Conclusion.—Intravenous valproate appears to be safe and effective for the acute treatment of migraine. Double-blind, placebo-controlled studies to further investigate the use of this agent in acute treatment of migraine attacks are warranted.