Duration of valproic acid monotherapy correlates with subclinical thyroid dysfunction in children with epilepsy.
To identify potential risk factors for the development of subclinical hypothyroidism following long-term valproic acid monotherapy in children with epilepsy. Serum levels of thyroid-stimulating hormone, free thyroxine, free triiodothyronine, thyreoglobulin antibodies, and thyroid peroxidase antibodies were determined in 41 patients and in 41 sex- and age-matched healthy children. Mean valproic acid treatment duration was 2.80±1.96 years. The valproic acid group had higher serum thyroid-stimulating hormone (p<0.001) and free triiodothyronine (p<0.05) levels compared to the control group. Serum thyroid-stimulating hormone and free triiodothyronine were above the upper limit for healthy controls in 34% and 32% of patients, respectively, and no clinical features of thyroid dysfunction were observed. Duration of valproic acid monotherapy for less than four years was a risk factor for elevated thyroid-stimulating hormone levels. One third of children with normal range serum valproic acid levels may have elevated serum thyroid-stimulating hormone and free triiodothyronine levels, especially in the first four years of treatment.
Faculty of Pharmacy, University of Belgrade.
Violeta
V
Ilić
Faculty of Medicine, University of Belgrade, University children's hospital, Belgrade, Serbia.
Dragana
D
Bogićević
Faculty of Pharmacy, University of Belgrade.
Branislava
B
Miljković
Faculty of Medicine, University of Belgrade, University children's hospital, Belgrade, Serbia.
Maja
M
Ješić
University children's hospital, Belgrade, Serbia.
Marijana
M
Kovačević
Faculty of Medicine, University of Belgrade.
Milica
M
Prostran
Faculty of Pharmacy, University of Belgrade.
Sandra Vezmar
SV
Kovačević
D000293:Adolescent; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013972:Thyrotropin / Q000097:blood; D013997:Time Factors; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood; D014635:Valproic Acid / Q000009:adverse effects* / Q000627:therapeutic use; D055815:Young Adult
D000927:Anticonvulsants; D014284:Triiodothyronine; D014635:Valproic Acid; D013972:Thyrotropin
children; epilepsy; thyroid function; valproic acid