Anti-seizure medication

Anti-seizure medication is the first line of treatment for epilepsy, allowing about 70% of those with the condition to achieve good seizure control.

This page covers how anti-seizure medications work, how effective they are, finding the right medication for you and getting the right dose, treatment plans and reviews, side effects and safety concerns, and stopping taking them.

Effectiveness of anti-seizure medications

The most common treatment for epilepsy in children and young people is medication. Medicines used to treat epilepsy are referred to as anti-seizure medications.

Anti-seizure medications do not cure epilepsy or treat the cause. Their purpose is to make seizures less likely to occur.

About 70% of those with epilepsy can achieve good seizure control through anti-seizure medications.

In the UK, there’s a wide range of anti-seizure medications.

How do anti-seizure medications work?

The brain is a very complex organ. Its complicated structures and processes are involved in even the simplest things we do every day. During seizures, for a number of reasons, the delicate balance of these processes is disrupted, causing sudden bursts of abnormal electrical activity. Anti-seizure medications work by affecting the brain in a way that stops this disruption and makes seizures less likely.

Some anti-seizure medications improve how particular chemical processes in the brain work. Others block or limit the effects of some chemical processes. Some medications work better for certain types of seizures than for others. There is no test to identify which will be best.  

So, finding the right anti-seizure medication can take time and be frustrating because the first drug may not be the best option.  But, don’t be discouraged – it’s important to persist.

Anti-seizure medications are always introduced at a very low dose and then gradually increased.  This is sometimes called titration. This allows your child’s body to get used to the medication and reduces the chances of unwanted side effects.

The right dose for children is calculated based on the child’s weight as they grow, which means medication doses are tweaked often. Increasing the dose to the right level may take a few months, so it’s vital to follow your doctor’s plan.

For some anti-seizure medications, it’s important to check how much medication is in a child’s bloodstream, so they’ll need regular blood tests.

Doctors may also need to monitor how a child’s other body systems, such as their liver, are responding to the medication.

As with all medications, anti-seizure medications can have side effects. You should receive a patient information leaflet with the medication that lists any known side effects and how likely they are to occur. Medicines for Children provides advice about giving medicines to your child. Find out more by clicking here

Some common side effects of anti-seizure medications include:

  • Drowsiness or lethargy
  • Irritability or mood swings
  • Changes in behaviour
  • Weight loss or gain and increases or decreases in appetite
  • Difficulty concentrating or learning
  • Memory problems
  • Dizziness or unsteadiness
  • Double vision
  • Hair loss

It’s important you keep a record of any responses to medication, changes in behaviour or possible side effects so you can tell your doctor.

Monitoring behaviour is especially relevant in younger children, as they may not be able to tell you if they are feeling nauseous (sick), but they may be irritable or off their food.

If your child develops a rash soon after starting an anti-seizure medication, or within a month, tell your doctor as quickly as possible. An allergic reaction can be serious.

Long-term treatment with some ant-seizure medications is associated with a loss of bone mineral density and greater risk of osteomalacia (softening of the bones). These include:

  • Carbamazepine (Tegretol and other brand names)
  • Phenytoin (Dilantin and other brand names)
  • Primidone (Mysoline)
  • Sodium valproate (Epilim)

Vitamin D and calcium supplements should be considered for people at risk.

Phenytoin (Dilantin and other brand names) is also associated with a greater risk of serious skin reactions in people of Han Chinese or Thai family background.

Carbamazepine (Tegretol and other brand names) and similar medicines, e.g. oxcarbazepine (Trileptal and other names) and eslicarbazepine acetate (Aptiom, Zebinix and other names), are associated with a greater risk of serious skin reactions in people of Han Chinese, Thai, European or Japanese background.

In discussion with the person with epilepsy, and parents or carers, as appropriate, doctors will develop an anti-seizure medication treatment plan, taking into account:

  • Sex
  • Age
  • The type of seizures [Link to About epilepsy_Level 3_Seizures_Landing page]
  • How often the seizures occur
  • How likely seizures are to occur again
  • The epilepsy syndrome, [Link to About epilepsy_Epilepsy syndromes_Level 3_Landing page] if this has been established
  • Results or findings from electroencephalogram (EEG) or magnetic resonance imaging (MRI) tests [Link to About epilepsy_Level 3_Diagnosing epilepsy]  
  • Whether treatment is needed
  • How and when anti-seizure medications need to be taken
  • The risks and benefits of anti-seizure medications, including reducing the risk of epilepsy-related death
  • How they might interact with any other medicines the person is taking
  • Any co-occurring conditions [Link to Parents and carers_Level 3_Common co-occurring conditions_Landing page]
  • The person’s preferences, and those of their parents or carers, as appropriate
  • Personal circumstances, including education, employment, likelihood of getting pregnant, driving, alcohol use and travel

Treatment with an anti-seizure medication usually starts once a diagnosis of epilepsy is confirmed. Treatment doesn’t usually start after just one seizure unless it’s clear why it happened and very likely that more seizures will follow. Doctors will consider starting treatment after one unprovoked seizure, if:

  • There are signs of damage to the brain, spinal cord, muscles or nerves
  • EEG test results [Link to About epilepsy_Level 3_Diagnosing epilepsy] show definite epileptic activity
  • Following discussion of the risk of further seizures, the person or their family or carers, as appropriate, think the risk is unacceptable
  • Brain imaging test results [Link to About epilepsy_Diagnosing epilepsy_Level 4_Neuroimaging (brain scans)] show a structural abnormality

See also Anti-seizure medications for girls and young women. [Link to About epilepsy_Epilepsy Treatments_Level 4_Anti-seizure medications for young girls and women]

There are different types of care plans. Medical teams should provide care plans for children and young people with epilepsy, as well as individualised emergency management plans.

Find out more about care plans and individualised emergency management plans. [Link to About epilepsy_Seizures_Level 4_Status epilepticus and emergency medication_Care plan and individualised emergency management plan]

Adults, children and young people with epilepsy, and their families or carers, as appropriate, can ask for a review of their care if they:

  • Have any concerns
  • Need support or their care needs change, e.g. to support medicines withdrawal, pregnancy planning or treatment review if seizures start again.

Children and young people with epilepsy should have access to an epilepsy specialist nurse. Epilepsy specialist nurses can provide information and support in a number of areas, including:

  • Concerns about how epilepsy and antiseizure medications can affect cognitive function, including memory, attention, concentration, learning and work
  • Taking anti-seizure medications as prescribed
  • The side effects of medication and how to cope with these
  • Changes to anti-seizure medication

Find out more about epilepsy specialist nurses. [Link to Parents and carers_ Level 4_Healthcare professionals – who's who]


Reviews for children and young people with epilepsy should:

  • Be discussed with the child or young person, and their parents and carers if appropriate
  • Be individually tailored to the child or young person's needs, preferences and type of epilepsy
  • Take place at least once a year

Young people with epilepsy usually move from paediatric to adult  healthcare between the ages of 16 and 18. Adults with epilepsy and, if appropriate, their parents and carers, can request a review of their care if they have concerns or need support, or their care needs change.

Examples include supporting medicines withdrawal, pregnancy planning or reviewing treatment if seizures recur. Adults with epilepsy should have a review at least once a year if they:

  • Have a learning disability
  • Have drug-resistant epilepsy
  • Are at high risk of SUDEP [Link to About epilepsy_Level 3_SUDEP]
  • Have a serious co-occurring conditions [Link to Parents and carers_Level 3_Common co-occurring conditions_Landing page]
  • Take anti-seizure medications known to have long-term side effects or to interact with other drugs
  • Can get pregnant and are taking sodium valproate (Epilim) or any other high-risk anti-seizure medication known to cause harm to children in the womb

Find out more about anti-seizure medications for girls and young women. [Link to About epilepsy_Epilepsy Treatments_Level 4_Anti-seizure medications for young girls and women]

Doctors should consider monitoring anti-seizure medication levels in people with epilepsy who:

  • Have uncontrolled seizures
  • Have side effects from their medication
  • Have a clinical condition that needs closer supervision, e.g. pregnancy or kidney failure
  • Don’t take their medication regularly as prescribed

If a person has been free of seizures for two years, they should be assessed to determine the risk of seizures starting again, if they stop their anti-seizure medication.  An epilepsy specialist should carry out the assessment if there’s any doubt or concern about the risks.

Before a child or young person stops taking their anti-seizure medication, doctors should discuss with them, and their families or carers, as appropriate:

  • Their individual risk assessment, including their risk of seizures starting again and the risk of SUDEP [Link to About epilepsy_Level 3_SUDEP]
  • The person's preferences and lifestyle, including whether they drive

If the decision is then made to stop anti-seizure medication, doctors should agree a plan with the person, and their parents or carers, if appropriate, based on the person's risk and personal preferences.

Most anti-seizure medications will be reduced gradually over a three-month period. Benzodiazepines and barbiturates (both are types of depressant drugs) are usually reduced over a longer period to lessen the risk of withdrawal symptoms. People taking multiple anti-seizure medications will stop them one at a time.

If seizures start again while or after stopping, the most recent dosage reduction will be reversed and the epilepsy specialist will offer guidance on what happens next.

After epilepsy surgery, [Link to About epilepsy_Epilepsy Treatments_Level 4_Neurosurgery for epilepsy] antiseizure medication can be stopped under guidance from the epilepsy surgery centre.