Epilepsy is a disorder of the brain that affects the nervous system. Epilepsy causes abnormal electrical activity in the brain, which leads to seizures. There are many types of seizure medication, all of which may have different side effects.

The cause of epilepsy is mostly unknown, although genetics, brain injury, illness, or structure of the brain may play a part.

People with epilepsy will require treatment, as soon after their diagnosis as possible. Although there is currently no cure for epilepsy, treatment can help to control and manage seizures.

Treatment may include diet, surgery, medical devices, and medications. There is a wide range of anti-seizure drugs, or anti-epileptic drugs (AEDs), to treat different types of seizures.

In this article, we look at some of the common epilepsy medications, their uses, potential side effects, and the importance of consulting a doctor to decide on a suitable treatment plan.

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Epilepsy seizures fall into one of two categories:


Focal seizures start in one area of the brain, and affect around 60% of people with epilepsy.

Doctors may classify focal seizures by the specific part of the brain in which they occur, such as medial temporal lobe or focal frontal lobe seizures.


Abnormal electrical activity in both sides of the brain causes generalized seizures.

People may experience different symptoms depending on the type of generalized seizure, which includes:

  • absence seizure
  • tonic seizure
  • clonic seizure
  • myoclonic seizure
  • atonic seizure
  • tonic-clonic seizure
  • secondary generalized seizure

People may also have unknown onset seizures if doctors are unable to find out which part of the brain the seizure begins.

The two main categories for AEDs are:

Narrow spectrum AEDs: These treat seizures that occur in a specific part of the brain, and treat focal or partial seizures.

Broad spectrum AEDs: These treat a range of different types of seizures. People may take these if they have more than one type of seizure, or the type of seizure is unknown.

People may take AEDs daily, starting with a lower dose and then gradually increasing as a doctor prescribes.

Common AEDs include:

Carbamazepine (Carbatrol or Tegretol)

Carbamazepine treats partial seizures. Side effects can include:

  • gastrointestinal upset
  • weight gain
  • blurry vision
  • low blood count
  • low blood sodium
  • in rare cases, rash

Clonazepam (Klonopin)

Clonazepam is part of a drug class called benzodiazepines. Clonazepam is longer acting in seizure prevention than diazepam and lorazepam, which are also benzodiazepines, although effects wear off over time.

Clonazepam can treat absence seizures and myoclonic seizures. Side effects of clonazepam can include:

  • sedative effects
  • impaired memory
  • mood changes
  • addiction

People may take clonazepam at night due to sedative effects.

Gabapentin (Neurontin)

Gabapentin is a safe, but not overly effective AED. However, this may be due to low doses. Gabapentin can treat some types of focal and partial seizures.

Side effects can include:

  • unsteadiness
  • weight gain
  • fatigue
  • feeling dizzy

Lacosamide (Vimpat)

Lacosamide is a relatively new AED, for treating partial and secondary generalized seizures. Side effects can include:

  • feeling dizzy
  • nausea and vomiting
  • headache
  • double vision
  • fatigue
  • memory problems
  • mood issues

Vimpat may cause more severe side effects, which affect blood counts, internal organs, or heart rhythm, although these do not occur frequently.

Lamotrigine (Lamictal)

Lamotrigine treats focal and generalized seizures. Side effects can include:

  • dizziness
  • fatigue
  • mild cognitive impairment
  • rash

Severe side effects are rare.

Levetiracetam (Keppra)

Levetiracetam is effective for a range of different seizures. Side effects can include:

  • dizziness
  • fatigue
  • insomnia
  • irritability
  • mood changes

Lorazepam (Ativan)

People may take lorazepam if they have clusters of seizures. It has fairly quick results, and may prevent seizures for 2-6 hours. It has similar effects to clonazepam.

Oxcarbazepine (Trileptal)

Oxcarbazepine has similar effects to carbamazepine with fewer side effects. It may cause low blood sodium.

Phenobarbital (Luminal)

Phenobarbital is an inexpensive and effective AED to treat focal and generalized seizures. Side effects can include:

  • sedative effect
  • cognitive and memory problems
  • depression
  • long-term bone problems
  • mildly addictive
  • risk of birth defects if pregnant

Phenytoin (Dilantin)

Phenytoin is for focal and generalized seizures. Side effects can include:

  • unsteadiness
  • moderate cognitive problems
  • potential risk of long-term cosmetic issues with skin or hair growth
  • osteoporosis risk

Pregabalin (Lyrica)

Similar effects as gabapentin. However, it may be more effective in treating seizures.

Topiramate (Topamax)

Topiramate is a treatment for all types of seizures. Side effects can include:

  • cognitive and memory problems
  • kidney stones
  • glaucoma, rarely
  • weight loss

Valproic acid (Depakote)

Valproic acid is a standard treatment for all types of seizures, and the most effective AED for generalized seizure types. Valproic acid does have more severe side effects though, which can include:

  • weight gain
  • tremor
  • hair loss
  • gastrointestinal upset
  • decreased blood count
  • liver or pancreatic injury
  • osteoporosis, over time
  • may cause birth defects in pregnancy

Vigabatrin (Sabril)

Vigabatrin is an effective treatment for partial seizures and infantile spasms.

Vigabatrin can cause serious eye problems, so regular eye testing is important for anyone taking the drug.

Zonisamide (Zonegran)

Zonisamide has similar effects to topiramate, although does not usually have a risk of glaucoma and may cause less cognitive impairment.

It is important that people discuss epilepsy medication options with their doctor, as a suitable prescription will depend on a person’s age, existing medical conditions, and type of seizures.

Doctors will also take into account a person’s lifestyle. Some AEDs can make people feel drowsy, so they may not be suitable for people who require high levels of concentration and alertness throughout their day.

Doctors will also check that any AED they prescribe will not negatively interact with any existing medication people are taking.

People will also need to tell their doctor if they are pregnant, planning to become pregnant, or nursing, to check if any medication is safe for them to take.

According to the National Institute of Neurological Disorders and Stroke (NINDS), the sooner people begin medication and other treatments for epilepsy after a diagnosis, the more successful the treatment may be.

AEDs are medications that can help to prevent seizures in people with epilepsy. People will need to continue to take AEDs for the preventative effects to work.

There are a wide range of AEDs, which each treat different types of seizures and each has different side effects.

People can discuss treatment options with their doctor, who can also go over the benefits and potential side effects of AEDS in an effort to find the best treatment for them.