Magnesium enhances the migraine prevention effect of valproate

This blog has many posts about the role of magnesium in the prevention of migraines and clinical trials of magnesium. Another study was just published by Iranian doctors in The Journal of Headache and Pain.

Unfortunately, like other studies, this one has a major flaw. Magnesium was given to all migraine sufferers, whether they were deficient in magnesium or not. If you are not deficient, taking extra magnesium will not help. For those who are deficient, however, the effect can be dramatic.

Another problem with this and several previous studies is the use of poorly absorbed salts of magnesium. In this case, magnesium oxide.

Patients in this study were divided into three groups. One group was given valproate (200 mg twice a day), the second group, valproate with magnesium oxide (250 mg twice a day), and the third group, magnesium oxide alone (also 250 mg twice a day). There were 82, 70, and 70 patients in each group, respectively.

Patients in the two groups that included valproate did better than those in the group taking magnesium alone. The combination of valproate with magnesium was more effective than valproate alone.

Surprisingly, the authors mention nothing about side effects. Valproate is one of the last drugs I use in migraine patients. It has many potential side effects, including weight gain, hair loss, tremor, nausea, and others. The majority of migraine sufferers are women of childbearing age and up to half of the pregnancies in the US are unplanned. So, another major reason I rarely prescribe this drug is that valproate is contraindicated in pregnancy. It can cause congenital malformations and developmental problems.