Topiramate has recently been approved by the FDA for prevention of migraine headaches in teens aged 12-18. Migraines are surprisingly common in this age group with one review stating a prevalence of 8-23% in 15 year olds. Topamax’s approval is a big development because it is the first preventive treatment for migraine to gain approval for the pediatric age group. It is also a big development because medications traditionally used for migraine prevention in adults, such as propranolol and amitryptilline, have either not been well studied, or have shown mixed or disappointing results when tried in children and adolescents with recurring migraine.
While the drug’s approval was based on a single manufacturer-sponsored study of 103 patients, topiramate has been suspected to effective for migraine prevention in this age group based on other clinical trials in children and adults (not only adolescents). The drug’s side effects are fairly well known since it has been on the market for many years for the treatment of epilepsy.
Who should consider topiramate for migraine?
1) Teens who have frequent, disabling migraines. “Frequent” means 2 or more headaches a month.
2) Teens who can’t get relief from abortive medication. This means that when you have a headache the medications you have tried either don’t stop the headache or cause intolerable side effects. This group of people would also include patients who cannot take certain medications because of vomiting (pills) or skin disease (patches).
How topiramate compares to other preventive therapies
The most effective dose in the study was found to be 100mg, given as 50 mg twice daily. Although remembering to take a twice daily medication can be a problem, skipping a dose is not likely to cause problems other than headache. Patients should not double up on doses if they miss a dose.
In the approval study, topiramate was compared to placebo. We do not know how topiramate compares to other potential treatments, since other studies have been of poor quality or design. Another study which will compare topiramate with amitryptilline, is currently enrolling subjects, but results are not expected until 2016.
Topiramate is available as a generic and is generally covered by most prescription plans, although it is not covered as a $4 generic at Walmart, Target, or similar pharmacies.
74% of patients who took topiramate in the trial had at least one side effect, compared to 48% of those who took placebo. The most common side effects were cold symptoms, tingling, and loss of appetite.
However, in people who take topiramate for epilepsy, other rare but serious side effects have been noted, including glaucoma, mood problems (including suicidal thoughts and behaviors), loss of sweating/overheating, kidney stones, and abnormal blood chemistries. Teens who take topiramate should be monitored for signs of depression/suicidality and for overheating and decreased sweating during hot weather and sports activities.
Topiramate is known to cause birth defects, including cleft lip and palate. The FDA recommends that in women of childbearing age who chose to use topiramate, “effective birth control should be used”. This poses a special problem for teen aged women with migraines, since oral contraceptives can sometimes aggravate migraines. More than half of teenaged migraine sufferers are female.
Topiramate is the only drug approved by the FDA for use in preventing migraines in teenagers. Not all drugs used in adults as migraine preventives are effective in teens. Topiramate has a significant side effect profile which may render it not worth taking in some patients, but it is a welcome addition to a profile of drugs which are all have big question marks in this age group.
Lewis, Donald. “Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Topiramate for Migraine Prevention in Pediatric Subjects 12 to 17 Years of Age.” Pediatrics. American Academy of Pediatics, 1 Mar. 2009. Web. 01 Apr. 2014.
Modi, Seema, and Dionne M. Louder. “Medications for Migraine Prophylaxis.” American Family Physician 73.1 (2006): 72-78. Print.
Topamax [package insert]. Janssen Ortho, LLC, Titusville, NJ; January 2014.
www.topamax.com/sites/default/files/topamax.pdf . Accessed April 1 2014.