Anti-seizure medications (also called anticonvulsants or antiepileptic drugs) are the most common treatment used to treat seizures and are prescribed by physicians after a discussion of the risks and benefits of the medication. Anti-seizure medications help to control/reduce seizures but do not cure the epilepsy. Treatment with only one anti-seizure medication is ideal (monotherapy) but some individuals may require more than one drug (polypharmacy). Approximately one half of people with epilepsy will have control of their seizures with an appropriate first anti-seizure medication and in general, two thirds of individuals with epilepsy will be seizure-free on medications. However, up to one third of individuals have epilepsy that does not respond to anti-seizure medications and are termed “refractory” or “treatment-resistant”.
There are over 20 different anti-seizure medications currently available and they differ in the way they work, the seizures they are best at treating, and the potential side effects. Thus physicians choose which medication to prescribe for the patients based on the type of epilepsy a person has and other factors such as age and gender. It is important for patients to know what the possible side effects are and to notify their physician if any side effects are experienced. The goal of treatment is always “No seizures, no side effects”, however this may not be achieved in all patients. Blood tests may be ordered for some anti-seizure medications to help with dosing decisions and to monitor for side effects. It is dangerous to stop medications or change doses on one’s own without medical advice. Anti-seizure medications work best when they are taken at regular intervals and without any missed doses.
As some of these anti-seizure medication levels may be affected by other medical conditions (kidney or liver disease), hormonal states (pregnancy), or other medications, it is important to tell your physician if you know of any changes to your medical state or if you are taking any new medications (such as the oral contraceptive pill) or other therapies like herbal remedies.
The duration of treatment is decided on an individual basis and in discussion with the physician. Some children have an epilepsy syndrome in which they will outgrow the tendency for seizures; thus anti-seizure medications can in some cases be discontinued under a physician’s care (such as Childhood Absence Epilepsy). Unfortunately we know that some of the epilepsy syndromes have a life-long tendency and a poor chance of seizure-freedom thus medication discontinuation will usually not be recommended (such as Juvenile Myoclonic Epilepsy). Discontinuation of medications will be only advised in keeping with each individual’s type of epilepsy and risk factors in mind. Overall, studies have shown that up to one quarter to one third of people with epilepsy may have their anti-seizure medications discontinued after a period of seizure-freedom.
The current available antiepileptic medications in Canada are:
*medications not available in Canada
Individuals with epilepsy who do not respond to two appropriate anti-seizure medications have drug-resistant epilepsy (DRE). For these individuals there are other therapeutic options such as dietary therapies and epilepsy surgery.