Anticonvulsants: Topiramate and Depakote (divalproex sodium)

Anticonvulsants are drugs that treat seizures (epilepsy). Two anticonvulsants also help to prevent migraine:^1,3

• Topiramate is a generic drug that is sold under different brand names: Topamax®, Trokendi XR®, Qudexy XR®. All three are approved for migraine prevention and epilepsy.^4-6
• Depakote® (divalproex sodium) is approved for migraine prevention, bipolar disorder, and epilepsy.^7,8

Topiramate and Depakote have proven efficacy for migraine prevention.¹ A third anticonvulsant, carbamazepine, is possibly effective.¹ Carbamazepine is not approved for migraine. Carbamazepine is mainly used to treat epilepsy and trigeminal neuralgia.

None of the anticonvulsants can be used as acute (or abortive) treatment for a migraine. They will not stop a migraine that has started.

How well do anticonvulsants work for migraine?

Depakote and topiramate were studied in people with episodic migraines. These drugs prevent about 1 to 2 migraine headaches per month.^4-9

These anticonvulsants cut the frequency of migraine in half for about 45% of patients.^10,11

It may take up to 8 weeks at the target dose to notice an improvement.¹ If you have at least some improvement, it may be worth continuing on the medication. Benefits may increase over 6 to 12 months of use.¹

What are the possible side effects of anticonvulsants?

All anticonvulsants carry warnings about two serious side effects:^4-8

• Increased risk of suicidal thoughts or behavior
• Increased risk of birth defects (and low IQ with Depakote)

Pregnant women should not take Depakote or topiramate. Women who could become pregnant should use effective birth control while taking Depakote or topiramate.

Combining alcohol with these drugs can cause sleepiness and dizziness. Do not drink alcohol while taking these drugs until you talk to your doctor. Always use caution when driving a car while taking Depakote or topiramate. Do not drive until you know how these drugs affect you.

Other possible side effects depend on the drug. Some are listed here, but there are more. For more information, consult your doctor or healthcare provider before taking these medications and let them know of all the medications you are currently taking. If you notice any new or worsening side effects when taking anticonvulsants, contact your doctor or healthcare provider immediately.

Topiramate

You cannot drink alcohol 6 hours before or after taking Trokendi XR.⁴

In people taking topiramate for migraine, common side effects include:^3-8

• Burning or tingling sensation, numbness
• Decreased appetite and weight loss
• Difficulty with memory and concentration
• Language problems
• Taste changes
• Gastrointestinal problems: nausea, diarrhea, stomach pain
• Colds

Serious side effects of topiramate include:

• Eye problems
• Decreased sweating and increased body temperature
• Kidney stones
• High ammonia levels
• Increased acid levels in the blood (metabolic acidosis)

These are not all the possible side effects of topirmate. Patients should talk to their doctor about what to expect with treatment with topiramate.

Depakote

In people taking Depakote for migraine, common side effects include:^3-8

• Gastrointestinal problems: nausea, indigestion, diarrhea, vomiting, stomach pain
• Weakness
• Sleepiness
• Dizziness
• Increased appetite and weight gain
• Tremor
• Back pain
• Hair loss

Serious side effects of Depakote include:

• Liver failure
• Pancreatitis
• Bleeding problems due to low platelet count
• Decreased body temperature

These are not all the possible side effects of Depakote. Patients should talk to their doctor about what to expect with treatment with Depakote.

How do anticonvulsants prevent migraine?

It is not known how topiramate or Depakote prevent migraine. These drugs affect several targets in the brain. Their action at those targets appears to calm the overexcited nerves. Overexcited nerves play a role in migraine.