Adverse effects of antiepileptic drugs.

Adverse effects of antiepileptic drugs (AEDs) are considered by patients to be at least as important as repetitive seizures in terms of quality of life. AED toxicity is frequent and contributes to a high proportion of treatment failures. Despite its high prevalence and clinical relevance, screening for adverse reactions to AEDs is not systematically included in everyday clinical practice; therefore it is very likely that it remains underestimated. Because there is little difference among AEDs in terms of efficacy, drug selection is often based on the adverse effects profile. AED toxicity is classified according to different parameters, such as severity, time of occurrence, organ system involvement, and mechanisms of action. Although most toxic reactions to drugs can be predicted from cumulative experience, prevention is not always possible, since multiple mechanisms and individual susceptibility to each drug participate in the final outcome. However, adverse effects can be reduced and appropriate action can be taken in time by means of a high degree of suspicion, knowledge of risk factors, and close follow-up. This article highlights factors to consider for detecting and managing AED adverse effects.