Thyroid functions as a parameter in monitoring of antiepileptic drugs.

Epilepsy is a chronic neurological disorder that is treated with multiple medications that can have significant side effects. This study investigated the potential effects of antiepileptic drugs on thyroid function. The participants in this study were epileptic adults who had been consistently monitored in follow-up care. The effects of antiepileptic drugs on the serum levels of the thyroid stimulating hormone (TSH), free T3 (fT3), and free T4 (fT4) of these patients were investigated retrospectively by comparing laboratory recordings in three defined periods: prior to antiepileptic drug treatment, between 6 months and 1 year of treatment (early stage), and after 1 year of treatment (late stage).   A total of 300 epileptic patients (F/M: 175/125) were included in the study. Significant differences in TSH and fT4 serum levels in the late stage compared to the pre-treatment stage ( A significant increase in TSH levels was found in epileptic patients on polytherapy. Our results give us the opportunity to highlight the potential unique or cumulative effect of antiepileptic drugs on thyroid hormone levels.