Which statement is true about a high plasma level of an AED?

• A. A high AED level may indicate the drug is not being excreted or the dose is too high.
• B. A high level means the patient will have fewer seizures.
• C. A high level indicates improved safety.
• D. A high level indicates the patient is hydrated.

Answer: (A)

High plasma levels of an antiseizure drug indicate drug accumulation, usually from a dose that is too high or from reduced clearance (impaired excretion or metabolism). When the drug builds up in the blood, the risk of toxicity increases, leading to side effects such as drowsiness, dizziness, ataxia, or confusion, rather than a guaranteed reduction in seizures. So a high level signals potential toxicity and the need to reassess dosing or organ function. Hydration status isn’t a reliable indicator of a high level, and a higher level does not mean better safety or fewer seizures.