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Anti-seizure medication

Also called anti-epileptic drugs or anticonvulsants

Key points about anti-seizure medication

Anti-seizure medications are the main way of preventing seizures in people with epilepsy.
Anti-seizure medications work by stabilising the electrical activity of your brain.
Find out how to take them safely and about possible side effects.

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Anti-seizure medications (ASM) aren't a cure for epilepsy, they're used to control or reduce seizures.

ASMs work by stabilising the electrical activity of your brain. Up to 70% (7 in 10) of people with epilepsy could have their seizures completely controlled with anti-seizure medications. Read more about epilepsy(external link).

Anti-seizure medications available in Aotearoa New Zealand

There are several different anti-seizure medications available in Aotearoa New Zealand.

Commonly prescribed anti-seizure medications

Use effective contraception when taking sodium valproate (Epilim ®) or topiramate

Sodium valproate or topiramate aren't suitable for people who could become pregnant.

If you’re a person of child-bearing age and you could possibly get pregnant, you should avoid valproate or topiramate, if possible.
If you use it during pregnancy, there's a risk of harm to your unborn baby, as well as long-term developmental disorders once they are born.
If these medicines are the best choice for you despite this, it’s important you understand the risks.
Talk to your healthcare provider about this and ensure you use 2 methods of effective contraception so you avoid unplanned pregnancy.

If you can father children

If you can father children, talk to your healthcare provider about the potential risks to a child while you're taking sodium valproate and for 3 months after you've stopped taking it. It's important to ask about options and plan ahead if you wish to start a family.

Note: All anti-seizure medications have the potential to harm an unborn child, but the risks are higher with sodium valproate and topiramate than some others, especially early in your pregnancy and if you're taking higher doses. Read more about epilepsy and pregnancy and epilepsy and contraception.

Other anti-seizure medications
acetazolamide clonazepam ethosuximide(external link) gabapentin (external link) lacosamide oxcarbazepine	phenytoin(external link) phenobarbital(external link) pregabalin(external link) primidone vigabatrin midazolam

Some anti-seizure medications are more suitable for different seizure types than others. Read more about the different types of seizures. The following is a guide to the main anti-seizure medications used for different seizure types:

Type of seizure	Anti-seizure medication options
Absence seizures	sodium valproate, ethosuximide, lamotrigine
Myoclonic seizures	sodium valproate, clobazam, levetiracetam, topiramate
Atonic and tonic seizures	sodium valproate, lamotrigine
Generalised tonic-clonic seizures	sodium valproate, lamotrigine, carbamazepine, oxcarbazepine, levetiracetam, clobazam
Focal seizures	carbamazepine, lamotrigine, sodium valproate, levetiracetam, oxcarbazepine, topiramate, lacosamide.

All anti-seizure medication can have side effects but the majority of people don’t get side effects.

Some side effects may impact on your lifestyle more than others and they can be life-threatening.
Common side effects when starting anti-seizure medication include tiredness, feeling sleepy, dizziness, dry mouth, feeling sick (nausea), diarrhoea (runny poos) and stomach upset. These usually go away as your body gets used to the medicine.
Life-threatening side effects that are possible with some anti-seizure medication include severe skin reactions, problems with your liver and problems with your blood cells such as your white blood cells or platelets.

Talk to your healthcare provider about possible side effects of your medicines. To help reduce your chance of side effects, your healthcare provider may:

start you on a low dose, then gradually increase it – this allows your body to slowly get used to the medicine
ask you to have blood tests to make sure you’re taking the right dose and check you don't have serious side effects.

The decision about when to start medication can be difficult. One seizure may not mean that you will have another, and a second seizure may not occur until years later.

A common option after a first seizure is to wait and see. If you have a second seizure within a few months more are likely, so it may be a good idea to think about starting anti-seizure medication.

Assessing the benefits and risks

The decision to start anti-seizure medication should be made by thinking about the benefits and risks of starting the medicine. This will depend on how your seizures affect you and how often they happen.

The following are risks and benefits of ASMs to think about before making your decision.

Risks of taking anti-seizure medicines

Having side effects from the medicine.
Needing to remember to take your medicine regularly.

Benefits of taking anti-seizure medicines

Reducing or stopping your seizures so they don’t interfere with your day-to-day life. Up to 70% (7 in 10) of people with epilepsy could have their seizures completely controlled with anti-seizure medications.
Reducing the chance of accidents or injuries that can happen when you have a seizure.
Reducing your worry that you’ll have a seizure.
Reducing the chance of getting status epilepticus. This is when you have seizures that continue without stopping, or a series of seizures that happen for 30 minutes without you recovering in between. This can happen with any seizure type.
Reducing the chance of SUDEP (sudden unexplained death in epilepsy patients). Read more about SUDEP(external link).

Deciding on which anti-seizure medication is best for you depends on many things, such as:

your type of seizures
your type of epilepsy
your age
the possible side effects of the anti-seizure medications and how they might impact on your lifestyle
other medicines you're taking for other conditions, and possible interactions with these
whether you're planning a pregnancy – read more about epilepsy and contraception
whether you're pregnant. Read more about:

Your healthcare provider can discuss the best medicine for you. It may take some time to find the anti-seizure medication that works best for you.

In most cases, only 1 anti-seizure medication is needed to prevent seizures, but some people may need 2 or more medications.

Anti-seizure medications (ASM) are usually available as tablets, capsules and liquids. If you find taking tablets difficult, ask your doctor to prescribe you something easier to swallow – some tablets can be chewed or crushed.

ASM is usually taken once or twice each day. Sometimes it's taken 3 times a day. It’s important to take it regularly, as prescribed by your healthcare provider, because missing a dose can increase the risk of having a seizure. Read more about tips for remembering to take medicine.

Once you're taking anti-seizure medication, it’s a good idea to get advice about what to do if you ever forget to take it. The advice your healthcare provider gives you when you miss a dose will depend on which epilepsy medicine you're taking, and how many times a day you take it.

Anti-seizure medicines don't cure epilepsy, but they can stop the seizures from happening. For some people, having epilepsy is a lifelong condition and they will need to continue taking medication.

If you haven't had a seizure for 2 or more years, you may want to discuss coming off your treatment with your doctor. It will depend on several things, including the possible impact of seizures returning.

Coming off ASM

When coming off anti-seizure medication, it's important to do it slowly. Stopping treatment suddenly is dangerous – it can cause seizures to start again, or happen more often and last longer than before.

You can plan with your doctor:

how to come off the medication slowly
what to do if your seizures start again.

If seizures do start again and you go back on medication, you may have to start at a low dose again until your body gets use to it. Always talk to your healthcare provider before re-starting anti-seizure medication.

Epilepsy | Mate hukihuki
Epilepsy and contraception
Epilepsy and pregnancy
Epilepsy topics | Mate hukihuki

The following links provide further information about anti-seizure medication. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Medicines for epilepsy, mental health and pain can harm your unborn baby(external link) ACC, NZ
Epilepsy(external link) Better Health Channel, Australia
New to epilepsy treatment(external link) Epilepsy Society, UK
About epilepsy: the basics(external link) Epilepsy Foundation, US