Anticonvulsants also reduce migraine frequency
A 2004 Cochrane review of anticonvulsant drugs for migraine prophylaxis found that anticonvulsants, as a class, reduce migraine frequency by about 1.3 attacks per 28 days when compared with placebo (based on 10 trials [N=902]). When analyzing data on relative frequency of migraines, data from 13 trials (N=1773) were combined and showed that anticonvulsants more than doubled the number of patients with a 50% or greater decrease in migraine frequency relative to placebo (relative risk=2.25; 95% CI, 1.79-2.84; NNT=3.9; 95% CI, 3.4-4.7).11
Other drugs to keep on your radar
Agents available in the United States that have at least limited evidence supporting their use to prevent episodic migraine include gabapentin, lisinopril, candesartan, memantine, riboflavin, magnesium, feverfew, coenzyme Q10, butterbur, and melatonin.
Drugs so far proved ineffective in preventing episodic migraine include clonidine, carbamazepine, clonazepam, vigabatrin, oxcarbazepine, zonisamide, lamotrigine, nifedipine, and acetazolamide. Botulinum toxin type A given by intramuscular injection in the head and neck region has demonstrated limited efficacy in chronic headache disorders, but doesn’t prevent episodic migraine.12
Recommendations
The 2000 guidelines of the American Association of Neurology address Group 1 (first-line) drugs and Group 2 drugs:
Group 1 drugs (medium to high efficacy, good strength of evidence, and a range of severity [mild to moderate] and frequency [infrequent to frequent] of side effects) include amitriptyline, divalproex sodium, propranolol, and timolol.
Group 2 drugs (lower efficacy than Group 1, or limited strength of evidence, and mild to moderate side effects) include aspirin (but not combination products), atenolol, fenoprofen, feverfew, flurbiprofen, fluoxetine, gabapentin, guanfacine, ketoprofen, magnesium, mefenamic acid, metoprolol, nadolol, naproxen, nimodipine, verapamil, and vitamin B2.13
Topiramate was still under study when the guidelines were released and wasn’t approved by the US Food and Drug Administration for migraine prophylaxis until 2004. The 2000 guidelines are undergoing revision.