Value of drug level concentrations of brivaracetam, lacosamide, and perampanel in care of people with epilepsy.

Plasma levels at a given time point did not allow conclusions to be drawn about seizure control or the occurrence of AEs. Our findings indicate that efficacy and tolerability cannot be predicted based on averaged data from a single plasma measurement due to high interindividual variability. Instead, individual reference values should be established when sufficient clinical data are available, in line with the 2008 International League Against Epilepsy position paper on therapeutic drug monitoring.