As if having frequent migraines isn’t painful enough, figuring out which medication—or combination of medications—is right for you can be a major challenge. Thankfully, several therapeutic options exist for both preventing and relieving pain. That’s good news for the 38 million Americans who suffer from migraines.
One of those options, Topamax (i.e. topiramate), is widely prescribed as a preventive migraine medication, despite its original use as an antiepileptic drug for people with a history of seizures.
In fact, according to Dr. Deborah I. Friedman, professor of Neurology at University of Texas Southwestern Medical Center and member of the American Headache Society, since being approved for migraine treatment in adults in 2004, topiramate is actually the most commonly prescribed oral preventative medication for migraines in the United States.
Why is an antiepileptic drug prescribed so frequently to treat migraines? Actually, that piece of the puzzle is still unknown.
“Topiramate works via different mechanisms, and it’s not clear which one is important for migraines,” Dr. Friedman says, explaining that topiramate works along sodium and calcium channels in the body, as well as on different receptors where nerves send signals.
As far as the discovery that topiramate could improve migraine symptoms, it was largely accidental. Friedman says epilepsy patients reported an improvement in their migraine symptoms while taking topiramate and other similar drugs.
What’s the dosage?
According to Dr. Danny Park, section head of neurology at Swedish Covenant Hospital in Chicago, the dosage for migraines is usually less than it is for epilepsy, with most doctors starting low and increasing the amount gradually over time.
“Typical dosing starts with 25 milligram tablets twice daily,” he says. “To mitigate adverse effects, I typically increase by 25 milligrams daily every week … [with the] maximum dose being around 100 milligrams twice daily.”
Could topiramate work for me?
You don’t have to be a chronic migraine sufferer (i.e. someone who has 15 or more migraine days per month, according to the American Migraine Foundation) to benefit from a preventive medication like topiramate. But Dr. Friedman says the patients who respond to the drug usually have a few other things in common.
“We think about migraine prevention therapies in people who have at least four headache days per month with severe disability from migraines,” she says, meaning that your migraines prevent you from performing your usual daily tasks.
Also included are people who have inadequate relief from acute therapies for migraine and those who have special kinds of migraine (like hemiplegic or brainstem aura) regardless of the frequency.
However, topiramate is not suitable for everyone. Friedman says it cannot be taken during pregnancy, and that she would “think twice” about prescribing it to someone with a history of calcium-based kidney stones because some research indicates topiramate can increase the risk of developing them.
What side effects will I have?
Though topiramate can be successful in reducing the frequency and severity of migraines, that success often comes at a price—many people struggle to tolerate the common side effects of the drug, which Dr. Friedman says may include:
- a tingling, pins-and-needles sensation in the extremities or face
- loss of appetite leading to weight loss
- brain fog
Dr. Park adds that these side effects can be experienced across the range of dosages for topiramate depending on the individual patient.
“I have some patients who get to 100 milligrams twice daily [without side effects] and unfortunately some patients who do not tolerate even 25 milligrams daily,” he says.
The bottom line
It may take a while for you to feel the full benefit of topiramate on your migraines—Dr. Friedman says many people see improvement in the first month, but it can continue improving for the first year. She also says that past clinical trials have shown 50 percent of people feeling 50 percent better on topiramate, with some reporting an even higher response rate.
But side effects are topiramate’s biggest downside; some people simply can’t tolerate them.
“It’s a ‘love it or hate it’ drug,” says Dr. Friedman, “and sometimes people are afraid to take it because they hear about the side effects. But not everyone gets them, so it’s important to be open-minded about it.”