Abstracts

Antiepileptic drugs (AEDs) may affect serum thyroid hormone concentration and lipid levels. The aim of the present study was to explore such pharmacological effect of AEDs by evaluating thyroid function and lipid profile in patients receiving AEDs.
We compared 45 patients (22 men and 23 women) with epilepsy (range, 20-51 years; mean, 31.2[plusmn]7.7) who have been on long-term AED therapy (range, 12-120 months; mean, 51.8[plusmn]28.24), to 45 age, sex and weight matched healthy controls. Patients with diseases other than epilepsy or those taking medications other than AEDs were excluded. To analyze, the patient group was divided into two categories: those taking hepatic enzyme inducing AEDs (phenytoin, phenobarbital, carbamazepine) (n=36), and those taking an AED that is not enzyme inducing (valproate) (n=9). We measured serum free T4, thyroid stimulating hormone (TSH), thyroid peroxidase (TPO), thyroid globulin antibody (TGAb), total cholesterol (TC), high density lipoprotein (HDL), free fatty acid (FFA), apolipoprotein A (Apo A), apolipoprotein B (Apo B). The blood samples were obtained at 8:00 a.m. after an overnight fasting.
Mean age, sex, body mass index (BMI) did not differ between the two groups. Free T4 level was lower only in patients taking enzyme inducing drugs compared to the controls (p[lt]0.05), but there was no difference between patients taking the non-inducing drug and controls. There was no correlation between free T4 level and the duration of therapy (r=-0.063, p=0.68). TSH, TPO and TGAb levels did not differ between the groups. Lipid profile, TC, HDL, LDL, FFA, Apo A, and Apo B levels did not differ between the groups.
Hepatic enzyme inducing AEDs decrease the free T4 level independent of the duration of therapy. This suggests a need for careful monitoring of thyroid hormone levels in patients receiving AEDs. In contrast to previous reports, AEDs didn[apos]t affect serum lipid and lipoprotein levels in our Korean patients.