Safety issues around misuse of antiepileptics.

INTRODUCTION: Drug misuse is a deliberate or accidental (by omission) nonadherence to medical recommendations, which may range from inappropriate use (missed, increased, or lowered doses or even complete discontinuation of therapy) to compulsive overdosing. Currently, this phenomenon affects as many as 20 - 80% of epileptic patients. AREAS COVERED: Long-standing research has enabled the identification and understanding of factors behind the phenomenon of nonadherence to medical recommendations. An inappropriate use of antiepileptic drugs usually has serious health implications for both children and adults. These involve increased frequency of seizures in patients who lower their doses or discontinue therapy, which may often lead to pathologies. On the other hand, patients who increase or take extra doses expose themselves to toxic effects of antiepileptic drugs. In both cases, there is an increased need for hospitalization, which further implies extra healthcare costs. The most misused antiepileptic drug is gabapentin (53%), whereas the least misused are lamotrigine, levetiracetam, and phenytoin (all drugs at 32%). EXPERT OPINION: The prevalence of misuse of antiepileptic drugs among epileptic patients is comparable to that observed in other chronically ill individuals. Preventive strategies have to be based on the reasons leading to nonadherence.