Antiepileptic drugs: What are they? What are they used for? Types, Side Effects, Precautions and Interactions

These types of medications are the main form of treatment for people with epilepsy.

And up to 70% (7 out of 10) people with epilepsy could have their seizures completely controlled with antiepilectic drugs.

There are about 26 antiepilectic drugs used to treat seizures, and different antiepilectic drugs work for different attacks. Here we explain what the different antiepilectic drugs are, what types of seizures or epilepsy they are used for, as well as essential information on average dosages and common side effects.

There are three ways to find information about antiepilectic drugs:

  • By the generic name.
  • By the mark of the particular type.
  • Because of the type of seizure or seizure you have.

Antiepileptics are a class of medications that try to prevent rapid and repetitive stimulation of the brain that causes seizure activity, as in epilepsy.

Members of this class of drugs include carbamazepine, valproate, lamotrigine, oxcarbazepine, gabapentin, levetiracetam, pregabalin, tiagabine, topiramate, vigabatrin, acetazolamide, and sultiama.

What are antiepileptic drugs used for?

Antiepileptic drugs are used to prevent seizures and associated complications. They are also indicated for the acute treatment of seizures, including status epilepticus and febrile seizures.

When to use antiepilectics?

Before starting treatment, your doctor may exclude non-epileptic causes, such as air retention seizures, arrhythmias, and pseudo seizures.

The type of epilepsy is then classified based on the description of the seizures, neurological examination, EEG findings, and neuroimaging. It is recommended to avoid precipitants if possible (eg, medications, sleep deprivation, alcohol withdrawal).

Antiepileptic medication is started when the impact of additional seizures outweighs the risks of treatment.

Treatment is generally indicated when 2 or more seizures have occurred in 6-12 months, except when there is a clear preventable precipitant or with some types of seizures, but this will be determined by your doctor.

The goal of treatment is to prevent seizure recurrence preferably with monotherapy to minimize adverse effects. Non-compliance is a common cause of treatment failure and therefore it is important to adhere to the treatment recommended by your doctor.

If the seizures are not controlled by the maximum tolerated dose of the first antiepileptic drug, it can be replaced by a second drug. The second drug is added to the first, and once the patient is stabilized with a suitable dosage, the first drug is gradually withdrawn.

Types of antiepileptic drugs

If monotherapy trials fail, combination therapy (with multiple drugs) is often used, but proper seizure control is more difficult.

The specific diagnosis of the type of seizure is the most important factor in the selection of medications; however, your doctor will choose the best treatment for you.

Tegretol (carbamazepine): Often considered the drug of choice for partial seizures.
Epilim (Valproate) is considered the first-line treatment for generalized seizures.

Lamictal (Lamotrigine): Can be used in adults as monotherapy in partial and generalized seizures, and appears to be as effective as carbamazepine.

It is also used as a complementary treatment.

Trileptal (Oxcarbazepine) : a compound structurally related to carbamazepine, it is effective as monotherapy or adjunctive treatment in partial seizures or generalized tonic-clonic seizures. It can be an alternative in patients who cannot tolerate carbamazepine.

Lyrica (pregabalin), Topamax (topiramate), Neurontin (Gabapentin), Keppra (levetiracetam), and Gabitril (tiagabine): These are newer antiepileptic drugs that are used primarily as adjunctive therapy.

Sabril (Vigabatrin) – Should be used only when all other appropriate drug combinations have failed. It can cause visual field defects in 20-40% of patients. Acetazolamide and sultiame are approved for epilepsy.

How do antiepileptics work?

Antiepileptic drugs have several mechanisms of action to try to prevent the rapid and repetitive stimulation of the brain that causes seizure activity:

  • Topamax (topiramato).
  • Tegretol (carbamazepina).
  • Epilim (valproate).
  • Amical (lamotrigine).

They work by blocking voltage-gated sodium channels and thus prevent repeated stimulation. Neurontin (Gabapentin) and Gabitril (Tiagabine) raise levels of GABA, a chemical messenger that stops repeated stimulation. This is also demonstrated with Topamax (Topiramate).

Lyrica (Pregabalin): is a newer drug that is a GABA analog with analgesic, anxiolytic and anticonvulsant activity.

The side effects of antiepileptic drugs

Side effects for each type of drug vary, but the most common side effects that occur in less than 10% of patients are:

  • Drowsiness.
  • Ataxia.
  • Dizziness.
  • Blurry vision.
  • Headache.
  • Nausea.
  • He retched.
  • Diarrhea.
  • Constipation.

Some of the few serious side effects that can occur in less than 1% of patients are:

  • Exfoliative dermatitis.
  • Stevens-Johnson syndrome.
  • Systemic lupus erythematosus.
  • Agranulocitosis.
  • Psychiatric disorders.

You may never experience any of these side effects, but if you have any concerns, talk to your doctor about it.

Anticonvulsant hypersensitivity syndrome

Carbamazepine, oxcarbazepine, and phenytoin are associated with this rare but serious syndrome. It usually occurs after 1 to 4 weeks of treatment and is characterized by fever, rash, and systemic organ involvement. If you notice any unusual skin rash or if you feel unwell, see your doctor as soon as possible.

Precautions when taking antiepileptic drugs

Pregnancy and antiepileptic drugs

Antiepileptic drugs can cause birth defects in pregnancy. Your specialist will evaluate the risks and benefits of the medications you take to make a decision. The risk increases with the amount of antiepileptic drugs taken.

Phenytoin, valproate, carbamezapine, and lamotrigine are category D gestations. Facial malformations, heart defects, and finger and nail deformities can occur with various antiepileptic drugs, particularly phenytoin (Dilantin), valproate (Epilim), carbamazepine. (Tegretol) and lamotrigine (Lamictal)).

There is also an increased risk of spina bifida with valproate and, to a lesser extent, with carbamazepine. Topiramate is Pregnancy Category B3. There are no studies using topiramate (Topamax) in pregnant women.

Your specialist will evaluate the risks and benefits and make sure you receive the best treatment. They may recommend that you use your medicine at the lowest effective dose and also start folic acid supplements four weeks before and continue for 12 weeks after conception. Consult your doctor if you are pregnant or planning to become pregnant.

Interactions with other medications

This class of medications can interact with other medications. Your doctor may try to avoid the combination or monitor it. If you have any concerns, talk to your doctor about it.

Hormonal contraceptives: If you start or stop taking hormonal contraceptives (for example, ‘the pill’) while taking antiepileptic drugs, your doctor may need to adjust the dose depending on how well your condition is being treated.