Topiramate is available in Canada by prescription only.

Known as

Topamax (Janssen-Ortho Inc.)


A broad-spectrum drug, effective against partial seizures (including secondary generalized tonic-clonic) and primary generalized tonic-clonic. Somewhat effective against absence and tonicatonic. Good for multiple seizure types or patients refractory to other drugs.

How to Use

Take topiramate as prescribed by your doctor with plenty of water. Topiramate may be taken with or without food. Loading dose = 25-50 mg/d, maintenance dose = 200-600 mg/d bidaily.

Side Effects

Reactions to topiramate are similar to reactions to phenytoin and carbamazepine. When you begin to take topiramate, you may experience drowsiness, dizziness, insomnia, muscular coordination problems, slurred speech, difficulties with word-finding, difficulty with concentration, headache, double vision, nausea, constipation, vomiting or skin rashes. If you notice the frequency of symptoms, or fever, ulcers in the mouth, rash, sore throat, easy bruising, or purplish-red spots on the surface of the skin, inform your doctor promptly. Some damage to connective tissue, coarsening of facial features and enlargement of the gums may also appear over a long period of use. The formation of kidney stones has been reported. Weight loss may occur.


 The elderly, people with diabetes, and those with impaired heart, liver or kidney function should be under close medical supervision while taking topiramate. Pregnant or breastfeeding women should inform their doctor. If you suffer from multiple seizures (including absence) inform your doctor prior to taking this drug. Use caution when operating a car or other machinery. Use with caution in combination with zonisamide, acetazolamide or the ketogenic diet, since these therapies also tend to induce renal stones. Remain well hydrated while using.


 Topiramate seems to have limited interaction with other anticonvulsants. Topiramate may decrease the effectiveness of oral contraceptives.When used in combination with other anti-seizure medication:

  • increases blood levels of phenytoin
  • decreases blood levels of valproate and oral contraceptives
  • blood levels increased by valproate
  • blood levels decreased by phenobarbital, phenytoin and carbamazepine
  • blood levels unchanged by gabapentin, lamotrigine, tiagabine, levetiracetam, oxcarbazepine and zonisamide
  • effects of felbamate unknown

Missed Dose

 Take your medication as soon as you remember. Do not double up on dosage to make up for a missed one. Resume your regular medication schedule.


 Store at room temperature between 15°C and 30°C away. Keep away from children, heat, light and moisture.


  • 25, 50, 100, 200, 300 and 400 mg tablets in bottles of 60
  • 15, 25, and 50 mg sprinkle capsules
  • Suggested therapy begins with 50 mg daily, gradually increasing to 200 to 400 mg daily
  • Recommended maximum daily dose: 800 mg

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The material offered at this site is to provide general information about epilepsy to the public. It is not intended to be taken as medical advice. Although all material presented at this site has been thoroughly researched and is believed to be correct, Epilepsy Ontario accepts no liability. Consult your physician and/or neurologist with any questions you have. People with epilepsy should never discontinue anti-epileptic medications or make changes in activities unless specifically advised to do so by an attending physician.