Topiramate (generic name) for Migraine Prevention — Brand names include Topamax, Trokendi XR, and Qudexy XR
Although the drug topiramate initially was developed for the treatment of epilepsy and received its first US Food and Drug Administration (FDA) approval for that purpose, it subsequently was shown to be effective for the prevention of migraine headaches and is FDA approved for that indication as well. Migraine and epilepsy share a considerable number of biologic and clinical features, and it follows that certain of the newer anti-epileptic drugs are effective for the prevention of migraine attacks as well as seizures. Precisely how topiramate prevents migraine is unclear, but generally speaking, it appears to reduce the genetically derived brain hyperexcitability that provokes migraine attacks in susceptible individuals.
While the clinical trials for migraine prevention that earned topiramate its FDA approval involved patients with episodic migraine (ie, less than 15 headache days per month), 1 large, randomized, placebo-controlled study indicated that topiramate may be effective for patients with chronic migraine as well (ie, 15 or more headache days per month). In a head-to-head study, patients with chronic migraine responded equally well to topiramate vs onabotulinumtoxin A injection therapy . . . but generally preferred the latter due to its more favorable side effect profile. At this point, onabotulinumtoxin A is the only therapy specifically approved by the FDA for the treatment of chronic migraine.
As a potent “brain active” medication, topiramate is not without potential side effects. Early in therapy, topiramate may cause nausea or other gastrointestinal distress. It also commonly produces an odd “pins and needles” sensation that may involve the hands, feet, or even the face; this side effect is benign, causes no neurologic injury, typically occurs early in the course of therapy, and is usually transient.
More concerning is the drug’s potential for causing behavioral or cognitive disturbance, the latter typically manifested by impaired recent memory, impaired concentration, or word-finding difficulties. While these cognitive side effects occur in a minority of patients and may be minimized by beginning with a low dose and gradually increasing the dosage each week, the “start low/go slow” technique does not totally eliminate the chance of their occurrence.
In rare instances, during the first 1 to 2 months of treatment, the drug may cause impaired vision by increasing intraocular pressure (“glaucoma”), and if you experience an unexpected disturbance of vision after beginning topiramate, you should stop the drug immediately and call your health care provider (HCP).
Topiramate not uncommonly causes weight loss, and the degree of weight reduction tends to correlate with the drug’s dose, the duration of therapy, and the individual’s baseline weight.
Finally, the drug may cause carbonated beverages to taste “flat.”
Do not take topiramate if you may be pregnant or intend to become pregnant while taking the drug.
The drug is not to be used by females who are pregnant, intend to become pregnant, or are sexually active and not practicing adequate contraception. Evidence has arisen to indicate that fetal exposure to the drug increases the risk of cleft lip or, less commonly, cleft palate; while the magnitude of that risk remains in some question, the FDA’s current best estimate is that the incidence of cleft lip is about 2 times higher in infants with known in utero exposure to topiramate as compared to the general population.
Dosing instructions for topiramate:
25 mg (one tablet) every night at bedtime (x 7 days)
50 mg (two tablets) every night at bedtime (x 7 days)
75 mg (three tablets) every night at bedtime (x 7 days)
100 mg (four tablets) every night at bedtime (x 7 days)
An individual patient may require a lower or higher dose based on efficacy and tolerability.
If you are experiencing intolerable side effects, stay at the lower dose for two weeks before attempting to titrate up the dose again. Many side effects will subside after the body has had time to adjust to a new drug.
Call us if you cannot tolerate topiramate due to side effects, so we can get you in sooner to start a new prevention plan. 601-366-0855
Headache © 2012 American Headache Society
John F. Rothrock, MD Professor and Chief of Neurosciences University of Nevada (Reno) School of Medicine Director, Renown Medical Center Neurosciences Institute