Evaluation of thyroid hormones, prolactin & insulin in children on prolonged valproate monotherapy for epilepsy

Epilepsy is defined as the occurrence of two or more unprovoked seizures. The cumulative life time incidence is 3%, and more than half start in childhood. Antiepileptic valproic acid is used in most of the cases as 1 st line therapy. The objective of the study was to evaluate the effect of valproate on thyroid hormone, insulin and prolactin in childhood epilepsy. A hospital-based, analytical cross-sectional study was conducted among the epileptic patients (1-12 years) who used valproic acid uninterruptedly for more than 6 months. Serum thyroid hormone levels including free thyroxine (fT 4 ) and thyroid stimulating hormone (TSH), insulin and prolactin were analyzed. There was a statistically significant variation of TSH (p value 0.001) among epileptic children receiving valproate monotherapy for more than 6 months. Other hormones fT4 (p value 0.832), prolactin (p value 0.654) and insulin (p value 0.453) did not show any significant variation. It was also shown that significant rise of TSH (p value 0.013) in children receiving valproate for more than 1 year and in children receiving valproate > 40mg/kg/day (p value 0.023) compared to others. The study did not reveal any statistically significant changes in insulin and prolactin level during valproate therapy. The present study showed that valproate causes significant alteration in TSH levels that is on valproate for more than 6 months. We have to check it periodically and also look for any sign or symptom of hypothyroidism appears or not.