Background
Antiepileptic drugs titration in epilepsy remains empirical. Since in practice seizure remission may be obtained with low doses, we aimed to determine if patients in remission have lower lamotrigine levels than those who continue experiencing seizures.
Methods
Retrospective analysis of the distribution of lamotrigine levels in people in remission and with ongoing seizures in a cohort. Remission was defined as the longest of either 3 times of the longest interseizure interval, or one year. Only through levels were considered.
Results
Between 2009 and 2014, we identified 93 adults, 10 were in remission. People in remission had significantly (p=0.018) lower serum levels (median 2.3 mg/l, range: 0.7-8.2) than those with ongoing seizures (median 5.4mg/l, range: 1.1- 18.2). We did not find any patient in remission with levels higher than 8.2 mg/l. Distribution of dosages also differed among the groups, but less significantly (p=0.03).
Conclusion
A correlation between lamotrigine serum levels and seizure response in term of remission appears to exist, and a ceiling level above which remission is unlikely is proposed. This could help to rationalise the titration of medication in drug- naïve patients with epilepsy.