Thyroid function profile in children with epilepsy receiving sodium valproate monotherapy: a cross-sectional study from North India

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Background: To evaluate the thyroid function profile in children with epilepsy receiving sodium valproate monotherapy for at least six months and to determine the prevalence and correlates of thyroid dysfunction. Methods: A hospital-based cross-sectional observational study was conducted at a tertiary care centre in Jaipur, Rajasthan, over 12 months (January–December 2024). Sixty-five children aged 1–17 years on sodium valproate monotherapy for a minimum of six months were enrolled by consecutive sampling. Thyroid function tests (free triiodothyronine (fT3), free thyroxine (fT4) and thyroid-stimulating hormone (TSH)) were measured at enrollment and compared with baseline values obtained prior to therapy initiation. Thyroid status was classified as euthyroid, subclinical hypothyroidism (TSH >5 µIU/ml with normal fT3 and fT4) or overt hypothyroidism. Associations with age, sex, valproate dose and duration of therapy were analyzed using the chi-square test and paired t-test. Results: After ≥6 months of valproate therapy, 44.62% of children developed subclinical hypothyroidism, 20.00% developed overt hypothyroidism and only 35.38% remained euthyroid. Paired t-test revealed significant increases in mean TSH (2.25±0.37 vs 5.49±2.68 µIU/ml; p<0.001), a decrease in mean fT4 (1.42±0.05 vs 1.20±0.18 ng/dl; p<0.001) and a mild increase in mean fT3 (3.61±0.16 vs 3.72±0.16 pg/ml; p<0.001). Thyroid dysfunction was significantly associated with older age (p<0.001), higher valproate dose (p=0.015) and longer duration of therapy (p=0.006), but not with sex (p=0.833). Conclusions: Sodium valproate monotherapy is associated with significant thyroid dysfunction in a substantial proportion of children, even within the first six months of therapy. Older age, higher doses and longer treatment duration are important risk factors. Routine monitoring of thyroid function is recommended for all children on long-term valproate therapy.