Topiramate

In Aotearoa New Zealand topiramate is available as tablets (25 mg, 50 mg, 100 mg and 200 mg) and sprinkle capsules (15 mg and 25 mg).

• The dose of topiramate will be different for different people.
• Your doctor will start you on a low dose and increase it slowly over a few weeks to reduce side effects such as drowsiness.
• Topiramate is usually taken twice a day but sometimes when starting topiramate it is taken once a day for a week or more. 
• Always take your topiramate exactly as your doctor has told you. The pharmacy label will tell you how much to take, how often to take it and any special instructions.

• Timing: You can take topiramate with or after food. Take topiramate at the same times each day.
  • If you are taking it twice a day, take your doses in the morning and night.
  • If you are taking it once a day, then it's best taken at bedtime.
• Swallow your tablets or capsules whole with a full glass of water, milk or juice. Don't chew them. If swallowing the capsules is a problem, you can open the capsules and carefully sprinkle the beads onto a small amount of soft food such as a teaspoon of porridge, yoghurt or custard. Swallow all of the food straight away. Don't chew the beads.
• Missed dose: If you forget to take your dose, take it as soon as you remember if it is within 4 hours of when your dose was due. But if more than 4 hours have passed since the dose was due, just take the next dose at the right time. Don't take double the dose.
• Keep taking topiramate every day. It may take a few weeks before you notice the full benefits of topiramate. Don't stop taking topiramate suddenly; talk to your healthcare provider before stopping because it can cause seizures if you stop taking it suddenly.

Here are some things to know when you're taking topiramate. Other things may be important as well, so ask your healthcare provider what you should know about.

Drink plenty of water 

Make sure you drink plenty of water to keep well hydrated while you are taking topiramate. It's important because topiramate can increase your body temperature and reduce sweating – especially during hot weather and when you exercise. This can put you at risk of getting dehydrated and can cause kidney stones. Tell your doctor immediately or ring Healthline 0800 611 116 if you get sudden pain in the stomach (tummy) area, difficulty passing urine (pee) or blood in your urine.

Taking other medicines

Topiramate can interact with some other medicines and herbal supplements, so check with your doctor or pharmacist before starting topiramate and before starting any new medicines or products.

Sex and pregnancy

Taking anti-seizure medicines while you are pregnant can potentially harm your unborn baby. If you are a sexually active female and are taking topiramate, you should use 2 effective means of contraception (such as an IUD and condoms) to avoid unplanned pregnancy. When you are taking topiramate it is extremely important to plan a pregnancy. You need to see your doctor 6 to 12 months before you would like to become pregnant so that you can reduce any risks to your baby. 

• All anti-seizure medicines in pregnancy have the potential to harm an unborn child but the risks are higher with some medicines, including topiramate, especially early in your pregnancy and at higher doses. If you have epilepsy, having seizures while you are pregnant can also harm your unborn baby, so it is important to keep taking an anti-seizure medication.
• Talk with your doctor to agree on a plan about how to manage your medicines and your dose. 
• If you are pregnant or think you might be pregnant, keep taking your medicine at the right dose, and contact your doctor, tell them you think you are pregnant and get an urgent appointment to see them.

For more information, read:

• • medicines for epilepsy, mental health and pain can harm your unborn baby(external link)
  • epilepsy medicines and pregnancy(external link)

Like all medicines, topiramate can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Problems with your eyesight

Topiramate can cause increased pressure in your eye. This can affect your eyesight and cause symptoms such as blurred vision, eye pain, nausea (feeling sick) and vomiting (being sick), and headache. This can happen within one month of starting treatment. If you have any of these symptoms, contact your doctor immediately. 

Other possible side effects

Read more about medicines and side effects and reporting a reaction you think might be a side effect.