Topamax for Chronic Migraines

July 3, 2006

Anti-seizure agent Topamax (topiramate) may decrease the frequency of chronic migraine events, according to a recent study. Topamax is indicated for epilepsy, but may be prescribed off-label for migraines.

Results showed that anti-epilepsy drug Topamax can reduce the frequency of migraine headaches and the total number of migrainous headache days in a month.

The study, by neurologist Stephen Silberstein, MD, of Thomas Jefferson University in Philadelphia, and colleagues, was presented at the American Headache Society’s 48th annual scientific meeting, in June 2006.

"Overall, many more patients on topiramate compared to placebo had a reduction in migraine and migrainous and had a better quality of life," said Dr Silberstein. "We have a safe, effective treatment for patients who have headache most of the days of their lives."

Clinical Trial

The multicenter, double-blind study included 165 chronic migraine patients randomized to receive Topamax 100 mg (or placebo) daily, after a 56-day screening and washout period.

Results showed that participants on Topamax fared significantly better than those on placebo according to several parameters:

The study’s primary endpoint was determining the average number of days per month that participants had a migraine or migrainous headache. This number significantly decreased among the Topamax group (6.4 days from a baseline value of 17.1 days), compared with placebo (4.7 days from a baseline value of 17.0 days).

The secondary endpoint, change from baseline in the 28-day rate of migraine headache days, also showed a significantly better result with Topamax (a 5.6-day reduction, compared with a 4.1-day decrease with placebo).

The severity of headaches also slightly, but significantly, decreased with Topamax – from baseline, severity decreased by 0.4 points (from 3.4 at baseline) versus a decrease of 0.2 points (from 3.3 at baseline) on a five-point severity-rating scale.

Finally, in terms of migraine-related quality of life issues, Topamax significantly improved all categories.

Adverse events related to treatment occurred in 65.0% versus 41.6% of participants in the Topamax and placebo groups, respectively, and 11.3% versus 6.2%, respectively, discontinued the study because of any adverse event.

The reported adverse events were no different from those reported in pivotal Topamax migraine trials. The most common events were paresthesia (an abnormal sensation, such as burning or tingling; 28.8% Topamax versus 6.8% placebo), upper respiratory-tract infection (13.8% versus 12.4%), fatigue (11.9% versus 9.9%) and hypoesthesia (decreased sensitivity to sensation; 9.4% versus 0.0%).

About 55% of participants in either arm completed the study.

Definition of Migraine

Dr Silberstein and colleagues used the International Classification of Headache Disorders, second edition, definition of “migraine headache” – but with a minimum duration of 30 minutes. They defined modified migrainous headache as a headache of moderate-to-severe intensity, accompanied by at least one other feature, such as like phonophobia (abnormal sensitivity to sound), photophobia (abnormal sensitivity to light) or nausea.

The definition of “chronic migraine” was similar to that defined by International Headache Society revised criteria – i.e., at least 15 headache-days over a 28-day period. A headache-day is a day with at least 30 minutes of head-pain; migraine or migrainous headache must occur on at least half of these days.

For More Information on Headache and Migraine, visit these websites:

Sources:
AHS: Epilepsy Drug Reduces Frequency of Chronic Migraines (CME/CE), MedPage Today, June 26, 2006.
Topiramate in Chronic Migraine: A Multicenter, Randomized, Placebo-Controlled Trial. Silberstein S et al, American Headache Society 48th annual scientific meeting, Abstract OR14, presented June 23, 2006.

Posted: July 2006


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