RELAPSE FOLLOWING DISCONTINUATION OF ANTIEPILEPTIC DRUGS - A METAANALYSIS

The estimates in the literature of the risk of seizure relapse after a ntiepileptic medications are withdrawn range from less than 10% to nea rly 70%. There is also little coherence regarding predictors of succes sful medication withdrawal. We performed a meta-analysis of the publis hed literature to date to determine the risk of relapse at 1 and 2 yea rs after discontinuation of medications and to examine the strength of association between the risk of relapse and three commonly assessed c linical factors: age of onset of epilepsy, presence of an underlying n eurologic condition, and an abnormal EEG. We established criteria for inclusion of a study in the analysis, and 25 studies met these criteri a. Overall, the risk of relapse at 1 year was 0.25 (95% CI, 0.21 to 0. 30) and at 2 years it was 0.29 (95% CI, 0.24 to 0.34). Relative to epi lepsy of childhood onset, epilepsy of adolescent onset was associated with a relative risk of relapse of 1.79 (95% CI, 1.46 to 2.19). Compar ed with childhood-onset epilepsy, adult-onset epilepsy was associated with a relative risk of 1.34 (95% CI, 1.00 to 1.81). Patients with rem ote symptomatic seizures were more likely to relapse than patients wit h idiopathic seizures; the relative risk was 1.55 (95% CI, 1.21 to 1.9 8). An abnormal EEG was associated with a relative risk of 1.45 (95% C I, 1.18 to 1.79). Although these figures help provide an estimate of a n individual's likelihood of relapse, they should not be used as the s ole basis on which to make the decision on discontinuation of medicati ons. Such a decision rests heavily upon weighing the risks and benefit s of continuing and discontinuing medications and includes considerati on of both the risk and the consequences of relapse.