The Effects of Antiepileptic Medications on Lipid Profile, Thyroid Panel, and Vitamin Level

Conventional antiepileptic drugs (AEDs) have been used for many years to treat epilepsy, and physicians are generally familiar with their side-effect profiles and potential drug interactions. However, AEDs affect patient vitamin and mineral levels in a manner that is not well understood. The goal of this study was to determine the relationship between AEDs and patient vitamins and mineral levels.

We conducted a retrospective analysis of liver enzyme levels, thyroid hormone levels, lipid profiles, and vitamin values (e.g., B12 and folic acid) in patients treated with carbamazepine, valproic acid, or levetiracetam at our institution. Patients were included in the study if their medical data included total cholesterol, triglyceride levels, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels obtained on follow-up at least three months after the start of antiepileptic treatment with carbamazepine, valproic acid, or levetiracetam. Patients were grouped according to the antiepileptic drug used. We analyzed liver thyroid function tests, lipid profiles, levels of B12, and folic acid levels using laboratory test results and compared the findings from each group.

Carbamazepine, valproic acid, and levetiracetam did not change the levels of liver enzymes such as aspartate transaminase and alanine aminotransferase (p values respectively: .802, .094). Cholesterol and LDL levels were lower in patients using carbamazepine (p values respectively: .005, .005), and no significant difference was observed for HDL and triglyceride levels (p values respectively: .400, .091). While thyroid-stimulating hormone levels were significantly higher in patients on medication than the control group (p=.007), the levels were still within reference ranges. No significant difference was found between tri-iodothyronine and thyroxine levels (p values respectively: .065, .053). The levels of B12 and folic acid were observed to be high in the group using carbamazepine (p values respectively: .049, .004).

Valproic acid and carbamazepine do not induce a significant increase in liver enzymes compared to levetiracetam, a new-generation antiepileptic medication, and they had no impact on lipoproteins such as HDL that are protective against coronary artery disease. These medications do not affect the levels of thyroid hormones in comparison to levetiracetam and the control group. Although carbamazepine and valproic acid are metabolized in the liver, liver enzyme monitoring is required; they have only affected liver enzyme values as much as levetiracetam and the control group.