Used for: Treatment and prevention of seizures and epilepsy, Migraine prevention
Chinese name:

What is Topamax?

Topamax is a brand product that contains Topiramate, which belongs to a class of miscellaneous anticonvulsant. It works by preventing the transmission of abnormal electrical signals in the brain to prevent migraine and treat various types of seizures, including primary generalised tonic-clonic seizures, and partial seizures.

How to use it?

Topamax is available as tablets.

For partial seizures and primary generalised tonic-clonic seizures

Patients 10 years of age and older:
Start with 25mg twice daily, and increase by 25mg per dose every week up to 100mg twice daily, then increase by 100mg per dose every week. The maintenance dose is 200 mg twice daily.

Pediatrics patients 2 – 9 years:
Start with 25mg once daily in the evening for the first week, and increase to 25mg twice daily in the second week. Then increase by 25-50 mg/day at weekly intervals over 5-7 weeks.

Maintenance dose varies depending on body weight:
11 kg: 150-250mg daily in two divided doses.
12-22 kg: 200-300mg daily in two divided doses.
23-31 kg: 200-350mg daily in two divided doses.
32-38 kg: 250-350mg daily in two divided doses.
>38 kg: 250-400mg daily in two divided doses.


For the prevention of migraine
Patients 12 years of age and older
Start with 25mg once daily in the evening, and increase by 25 mg per dose every week. The maintenance dose is 50mg twice daily.

What are the side effects of Topamax?

Common side effects of Topamax include burning and tingling sensations on the body, anorexia, weight loss, fatigue, dizziness, and upper respiratory tract infection.

Who should not take Topamax?

  • People who are allergic to any component of Topamax
  • Patients with metabolic acidosis
  • Pregnant and childbearing women

Pharmacist Tips:

  • Drink plenty of fluids to stay hydrated during the day. This can help prevent the risk of kidney stones while taking Topamax.
  • Do not stop taking Topamax abruptly as it can cause seizures.
  • Do not drive or operate machinery until you know the effect of the medicine.

Common dosing schedule: 
Topiramate can be taken with or without food.

This schedule is for reference only, adjustments may be made according to individual needs.


Some common medications Topamax may interact with:

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Topamax in Hong Kong?

In Hong Kong, Topamax is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Topamax in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Available dosage
  • 25mg / 50mg / 100mg (Tablets)
Drug class
Anticonvulsants, Central Nervous System Agents
Sub class
Carbonic Anhydrase Inhibitors, Miscellaneous Anticonvulsants
Generic Names
Other drugs in same class
Used for: Myoclonic seizures, Partial seizure, Primary generalized tonic-clonic seizures
Chinese name:
Used for: Ocular hypertension, Glaucoma
Chinese name:
Used for: Partial seizure, Primary generalized tonic-clonic seizures, Myoclonic seizures
Chinese name:
Used for: Treatment and prevention of acute mountain sickness, Glaucoma, Oedema, Epilepsy
Chinese name:
Used for: Migraine prevention, Treatment and prevention of seizures and epilepsy
Chinese name:
Used for: Treatment and prevention of acute mountain sickness, Oedema, Glaucoma, Epilepsy
Chinese name: