Stopping antiepileptic drug therapy
When a patient with epilepsy has not had a seizure for a long time, the only way to find out if drug therapy is still needed is to withdraw it. The decision to stop therapy must consider the patient's views. As the patient must stop driving during dose reduction and for 3 months after the last dose, many patients choose to continue therapy indefinitely.
Do not try to withdraw antiepileptic drugs until at least 2 years after the last seizure. When therapy is withdrawn after at least 2 seizure-free years, the risk of seizures recurring is about 50%. Factors that predict a high risk include:
- symptomatic (structural, metabolic, immune, infectious) epilepsy
- neurological abnormalities on examination
- a history of seizures that are difficult to control
- epileptiform abnormalities on EEG
- abnormalities on magnetic resonance imaging or computed tomography
- recurrence after past attempts to withdraw all antiepileptic therapy.
Usually the dose of antiepileptic drug is reduced over several months, but barbiturates and benzodiazepines (especially clonazepam) are reduced more slowly. If seizures recur, the patient should start therapy again on the previous effective dose—they can resume driving 1 month after this (see the national standards of fitness to drive1).
Juvenile myoclonic epilepsy has such a high recurrence rate that it is best not to withdraw therapy, at least not until many years without seizures of any type (including jerks).