Effects of antiepileptic drug on thyroid hormones in patients with epilepsy: A meta-analysis

Abstract

PurposeAs antiepileptic drugs (AEDs) are known to be associated with alterations in thyroid profiles, we aimed to carry out a meta-analysis to comprehensively assess the effects of AEDs on thyroid hormones in patients with epilepsy. MethodsWe searched the NCBI (PubMed), ISI Web of Science, EMBASE databases, and Cochrane Library to identify studies evaluating the association between AED use and thyroid hormone profiles in patients with epilepsy. Fixed or random effects meta-analysis was used to pool results across studies. ResultsIn all, 35 studies were included in our analysis. Out of a total of 997 patients in these studies, epileptic patients receiving AEDs showed an overall significant decrease in thyroxin (T4) and free T4 (fT4) and higher levels of thyroid stimulating hormone (TSH) than the controls (T4: standardized mean difference [SMD]=−1.839, 95% confidence interval [CI], −2.063 to −1.614; fT4: SMD=−1.190, 95% CI, −1.687 to −0.692; TSH: SMD=0.445, 95% CI, 0.031–0.858). Notably, the use of carbamazepine (CBZ) suggested a significant decrease in triiodothyronine (T3), T4, and fT4; phenytoin (PHT) use showed a decrease in T4 and fT4; and valproic acid (VPA) use was associated with decreased T4 and increased TSH. ConclusionOur study suggests that use of AEDs such as CBZ, PHT, and VPA, was associated with alteration of thyroid hormones among patients with epilepsy.