Epilepsy - Long-Term Treatment

Long-Term Treatment

Treatment with anti-epileptic drugs (AEDs) is usually initiated or strongly considered for the following patients:

• Children and adults who have had two or three seizures, unless there is either a long separation between seizures or the seizure is provoked by an injury or other specific causes. (In children, risk for recurrence after a single unprovoked seizure is rare. The risk even after a second seizure is low, even when the seizure is prolonged.)
• Children and adults after a single seizure if tests reveal any brain injury, or if specific syndromes put a person at special risk for recurrence, for instance, in cases of myoclonic epilepsy.

There is some debate about whether to treat every adult patient with an AED after a single initial seizure. Some experts do not recommend treating adult patients after a single seizure if they have a normal neurologic examination, EEG, and imaging studies. A 2005 study of patients with single or infrequent seizures found that while early AED treatment reduced the risk of seizure for a few years, it had no effect on long-term outcomes. This study also suggested that delaying AED treatment does not increase the risk of developing lifelong epilepsy.

Some doctors believe, however, that any adult who has a first seizure should begin on-going AED treatment, since 30 - 70% of these patients are likely to experience a subsequent event. According to one study, when young adults were given a single drug (usually carbamazepine) after a first generalized seizure, only 22% had a subsequent seizure compared to about 70% of those who were not given treatment.

Determining an Anti-Epileptic Drug (AED) Regimen

Most epileptic seizures can be controlled using a single-drug regimen. First-line AED drugs include phenytoin (Dilantin), carbamazepine (Tegretol, Carbatrol), and divalproex sodium (Depakote). Patients generally begin with low doses and build up until the seizures are controlled or a toxic reaction occurs. If a single drug fails to control seizures, then other drugs are added on. The specific drugs and whether more than one should be used are determined by various factors, including the patient's age and the seizure's type, frequency, and cause.

Treatment Success and Failure of AEDs

In a 2000 study that followed over 500 patients for 3 - 5 years, 63% of patients treated with AEDs become seizure-free. In the same study, drugs failed to control epilepsy in about 30% of patients. Those with the poorest chances of success were those who started AED treatment after more than 20 seizures, and those who failed to exhibit any benefit from their initial drug regimen. (In the latter case, subsequent drugs worked in only 11% of patients.)

Reasons for Failure. An AED's failure to reduce seizures can be attributed to factors such as: