Abstract
The aim of this study was to investigate the thyroid functions in children receiving
levetiracetam or valproate monotherapy. We retrospectively reviewed the records of
children with controlled epilepsy receiving valproic acid (VPA group) or levetiracetam
monotherapy (LEV group) for at least 6 months. Free thyroxine 4 levels (fT4) and thyroid
stimulating hormone (TSH) levels were compared between VPA group, LEV group, and age-
and gender-matched healthy children (control group). A total of 190 children were
included in the study: 63 were in the VPA, 60 in the LEV, and 67 in the control group.
Although there was no significant difference regarding average fT4 levels, higher
TSH levels were found in the VPA group when compared with the LEV and control groups
(p < 0.001 and p < 0.001, respectively). There was no significant difference in terms of fT4 and TSH
values in the LEV group when compared with the control group (p = 0.56 and p = 0.61, respectively). Subclinical hypothyroidism (defined as a TSH level above 5
uIU/mL with a normal fT4 level was detected in 16% of patients in the VPA group, none
in the LEV and control groups. Our study found that VPA therapy is associated with
an increased risk of subclinical hypothyroidism while LEV had no effect on thyroid
function tests.
Keywords
antiepileptic drugs - thyroid function - children
