General Information

Depakote ER is an extended-release product used to prevent or reduce the occurrence of migraines. It is indicated for the prevention of migraine headaches in adults; however, there is no evidence that it is useful in the acute treatment of migraine headaches. Depakote ER is provided in tablet form.

About 23 million Americans suffer from migraine headaches, and approximately 75% of migraine sufferers are women. Migraines may also include nausea and/or vomiting, as well as sensitivity to light and sound.

Clinical Results

The results of a multicenter, randomized, double-blind, placebo-controlled, parallel-group trial demonstrated the effectiveness of Depakote ER in the prevention of migraine headaches. Patients who experienced two migraine headaches in a four-week baseline period were randomized in a 1:1 ratio to Depakote ER or placebo and treated for 12 weeks. Patients began treatment on 500 mg once daily for one week, and were then increased to 1000 mg once daily with an option to decrease the dose back to 500 mg during the second week if intolerance occurred. 98 of 114 Depakote ER-treated patients (86%) and 100 of 110 placebo-treated patients (91%) treated at least two weeks maintained the 1000 mg once daily dose for the duration of their treatment. Treatment outcome was based on the reduction of the four-week migraine headache rate in the treatment period compared to the baseline period.

Two hundred and two patients (101 in each treatment group) completed the treatment period. The mean reduction in the four-week migraine headache rate was 1.2 from a baseline mean of 4.4 in the Depakote ER group, versus 0.6 from a baseline mean of 4.2 in the placebo group. The treatment difference was statistically significant. (from FDA Label)

Side Effects

Adverse effects reported with Depakote ER use include (but are not limited to) the following:

Nausea

Diarrhea

Vomiting

Abdominal pain

Dizziness

Tremor

Weight gain

Back pain

Depakote ER generally should not be administered to patients with hepatic (liver) disease or significant hepatic dysfunction.

Before using Depakote ER, a woman who can become pregnant should consider the fact that Depakote ER has been associated with birth defects, in particular, with spina bifida and other defects related to failure of the spinal canal to close normally.

Mechanism of Action

Divalproex sodium is a stable co-ordination compound comprised of sodium valproate and valproic acid in a 1:1 molar relationship and formed during the partial neutralization of valproic acid with 0.5 equivalent of sodium hydroxide. Chemically, it is designated as sodium hydrogen bis(2-propylpentanoate).

Divalproex sodium dissociates to the valproate ion in the gastrointestinal tract. The mechanisms by which valproate exerts its therapeutic effects have not been established. (from FDA Label).