In my experience Depakote works best for migraine headaches when rapidly infused. Anything longer than five minutes when used intravenously doesn't work.

In fact I once had a nurse stand on a chair after tapping my vein and simply squeezed the bag as hard as she could until the contents were empty, less than a minute later. One of the side effects of this treatment is it tends to make you nauseous, but for those who have had migraines, you know side effects are of little consequence as long as the damn headache is gone.