Antiepileptics

Antiepileptics, also called anticonvulsives, are usually used for treating epilepsy. Some antiepileptics are also successfully used for treating severe migraines. The three most important ones are listed below:

Topiramat

New information for the prophylactic effectiveness of Topiramat for migraine exists. This medication seems to be an option especially for patients who suffer from highly frequented or chronic migraine.

In a study, which was published in 2002, 469 patients who had 5 attacks on average took part in a 26 week long trial with placebos. The doses given were 50 mg, 100 mg and 200 mg per day. Primary objective was the reduction of the days with a migraine attack per month.

Patients who received doses of 100 mg, slowly increased over 8 weeks, showed a reduction from 5.4 to 3.3 days with a migraine attack per month (- 39%). Patients who took doses of 200 mg decreased their days with a migraine attack per month from 5.6 to 3.3 days per month (- 41%). The placebo group only showed a reduction from 5.6 to 4.6 days per month. 54% of the 100 mg group and 51% of the 200 mg group showed a reduction of the attacks of more than 50%. Consequently, the optimal dose is 100 mg.

The special feature of the treatment is the connected weight loss. While most other prophylactic medications limit the use because of unwanted weight gain, Topiramax causes an average weight loss of about 3.8%.

The substance is licensed in Germany under the name Topamax Migräne. The medication is supposed to reduce the frequency and severity of migraine attacks. The exact mechanism of action is not yet known. The substance has been used as Topamax for treating epilepsy for a while.

There it is part of the standard medication by and is used for life long therapy. The daily dose for migraine prophylaxis is less than in epilepsy therapyand is between 50 – 200 mg. This dose can be taken as a single or in two seperate doses. The doctor will adjust an individually needed dose.

Most patients tolerate the medication well. As more common but harmless side effects tingling sensations in, for example, arms and legs can occur and are mostly temporarily. In some cases a temporary potassium dose can help. Sometimes, slight changes in taste for example for sweet dessert can occur. Maybe this is the reason why  weight loss occurs in some patients over the course of the therapy. Enough fluids should be drunk (about 3 liters a day) to prevent kidney stones.

Side effects depend on the dose. 20% to 33% of the 100-200 mg group discontinued the treatment due to side effects. The main reason were tingling sensations in the legs comparable to pinpricks, lack of appetite, change in taste, trouble finding words, trouble concentrating and mood swings. After discontinuation of the medication the symptoms completely subside. Regular checks of liver enzyme levels every 6 weeks are necessary during treatment.

Most of the patients benefit from the medication if tolerated. In some patients trouble concentrating or disorders of the memory can occur. Also, in some very sensitive patients, changes in the mood with depressive disorders can occur or worsen. In this case it has to be decided if a reduction of the dose is possible or if the patient is unsuitable for the substance and if an alternative medications should be considered.

Valproic acid

In the last couple of years, valproic acid was recognized more and more as an effective medication for migraine prophylaxis. The very goof effects which is similar to the beta blockers was proven several times in controlled studies. The use of valproic acid has to be considered carefully because potentially severe and life threatening side effects can occur. While severe reactions of the skin are only described in individual cases, severe liver function problems did occur with a small but constant frequency especially in children and teenagers. The indication should be checked in every individual case before taking valproic acid especially because the approval for this indication doesn’t exist in Germany. Even though valproic acid is very effective, it should only be seen as a back up substance for now.

Gabapentin

Gabapentin has already been classified as a medication for migraine prophylaxis of 2nd choice by the American Academy of Neurology. A controlled study from the year 2001 showed a significant decrease of the number of migraine attacks and of days with with a migraine attack per month with a dose of 2400 mg compared to the placebo group. Only 13.3% of participants discontinues the study due to side effects, most often because of fatigue or dizziness. To definitely prove the importance of Gabapentin more studies are necessary especially comparative studies with other prophylactic medication. Gambapentin has not approved in Germany for treating migraine.