Clinical Question

Is topiramate (Topamax) an effective prophylactic medication for adults with episodic migraine?

Evidence-Based Answer

Topiramate in a dosage of 100 mg per day is effective for decreasing the frequency of headaches in adults with episodic migraine. (Strength of Recommendation: A, based on consistent, good-quality patient-oriented evidence.)

Practice Pointers

Migraine headaches are common, affecting approximately 18% of women and 6% of men in the United States.¹ Episodic migraine describes a headache frequency of fewer than 15 days per month as opposed to chronic migraine, in which headaches occur 15 or more days per month. Pharmacologic migraine treatment options include acute and preventive therapies. Population-based studies suggest that approximately 26% of persons who have migraines need preventive therapy, but only 13% use it.¹

Topiramate is an antiepileptic drug used as preventive therapy for migraines.² This meta-analysis studied whether topiramate was effective in reducing the occurrence of migraines and/or improving migraine-related quality of life in patients with episodic migraine. Seventeen prospective, controlled trials of topiramate were included in this analysis. Nine of these studies compared topiramate with placebo and found that it reduced headache frequency by 1.2 attacks per 28 days (mean difference = −1.20; 95% confidence interval [CI], −1.59 to −0.80). Patients taking topiramate daily were more likely to report a 50% or more reduction in headache frequency compared with patients taking placebo (relative risk = 2.02; 95% CI, 1.57 to 2.60). The number needed to treat for a 50% reduction in migraine headaches with topiramate vs. placebo was 4 (95% CI, 3 to 6).

Topiramate in dosages of 50 to 200 mg daily improves outcomes compared with placebo. A meta-analysis of three studies showed that the 100-mg dose was more effective at reducing headache frequency than the 50-mg dose (mean difference = −0.71; 95% CI, −1.32 to −0.10), and equivalent to the 200-mg dose. In trials that compared topiramate with placebo, seven adverse effects were reported by at least three studies: anorexia, fatigue, memory problems, nausea, paresthesia, taste disturbance, and weight loss. All adverse effects except nausea were significantly more common in persons taking 100 mg of topiramate daily vs. placebo. Topiramate is known to cause birth defects if taken during pregnancy, and should be used with caution in women of childbearing age.

Guidelines from the American Academy of Neurology, the American Headache Society, and the Canadian Headache Society list topiramate as a first-line agent to prevent episodic migraine. Other first-line agents are beta blockers (metoprolol, propranolol, and timolol); the antiepileptic valproate (Depacon); and butterbur, an herbal medication.³ The American Academy of Neurology suggests offering preventive treatment when an individual reports one of the following: six or more headache days per month, four or more headache days with at least some impairment, or three or more headache days with severe impairment or requiring bed rest. Only a few head-to-head drug comparison trials are available, and these suggest that topiramate is probably as effective for the prevention of migraines as other recommended first-line agents (e.g., propranolol, valproate).² In conclusion, topiramate in a dosage of 100 mg daily is a reasonable choice for migraine prophylaxis in patients with episodic migraine.