Even as they are beginning therapy with antiepileptic drugs (AEDs), many patients ask how long it will be necessary to continue the treatment. This question is difficult to answer.

Most, but not all, children and adults who are seizure-free for 2 years while taking AEDs will remain so if they stop taking their medications. It is impossible to prospectively identify which patients will remain free from seizures after their AEDs are discontinued, however.

The decision whether to taper AEDs must be made on an individual basis, with consideration given to the uncertainty of the risk of seizure recurrence and the potential risk of continuing AEDs.

The principal risk of discontinuing AED therapy is recurrent seizures. This risk generally poses less of a problem for children than for adults, who may be employed and dependent on driving.

The following factors imply an increased risk for seizure recurrence:

• readily identifiable brain pathology (e.g., brain tumor, congenital anomaly, cerebral contusion)
• seizure onset after age 12
• severe epilepsy before the initiation of AED therapy
• specific epilepsy syndromes (particularly juvenile myoclonic epilepsy)
• abnormal EEGs (applies only to children with idiopathic epilepsy)
• multiple seizure types occurring in the same patient

The benefits of medication withdrawal include:

• avoidance of side effects (such as teratogenicity, behavioral and cognitive impairment, and cosmetic effects)
• reduction of secondary psychosocial issues related to the diagnosis of epilepsy, of which AEDs are a daily reminder
• cost savings

How long does it take to stop?

When AEDs are withdrawn, special caution is warranted. The medication should be tapered, usually over weeks to months, rather than stopped abruptly. Abrupt discontinuation of any AED may increase the risk of seizures and status epilepticus. CNS depressants such as phenobarbital and the benzodiazepines especially may require months of very gradual withdrawal to minimize the risk of withdrawal seizures.

Adapted from: Schachter SC. Treatment of seizures. In: Schachter SC, Schomer DL, eds. The comprehensive evaluation and treatment of epilepsy. San Diego, CA: Academic Press; 1997. p. 61-74.
With permission from Elsevier (www.elsevier.com).
Reviewed and revised December 2003 by Steven C. Schachter, MD, Harvard Medical School