The Effect of Antiseizure Medications on Thyroid Functions in Children With Epilepsy

Area of Science:

• Pediatric Endocrinology
• Neurology
• Pharmacology

Background:

• Epilepsy affects children globally, requiring long-term management with antiseizure medications (ASMs).
• Some ASMs are known to cause thyroid dysfunction, necessitating monitoring.
• The impact of newer ASMs like levetiracetam on thyroid function in pediatric populations requires further elucidation.

Purpose of the Study:

• To evaluate the effects of four ASMs (valproate, phenobarbital, carbamazepine, levetiracetam) on thyroid function in children with epilepsy.
• To assess changes in serum thyroid-stimulating hormone (TSH) and free thyroxin (fT4) levels.
• To determine the incidence of subclinical hypothyroidism during ASM monotherapy.

Main Methods:

• A longitudinal study involving 181 pediatric patients on monotherapy with valproate, phenobarbital, carbamazepine, or levetiracetam.
• Regular monitoring of serum TSH and fT4 levels at baseline, 6, 12, and 18 months.
• Comparison of thyroid hormone levels and subclinical hypothyroidism frequency across different ASM groups.

Main Results:

• Valproate treatment led to significantly increased TSH levels and a higher incidence of subclinical hypothyroidism (16% at 18 months).
• Carbamazepine use resulted in lower fT4 levels compared to other ASMs at 12 and 18 months.
• Levetiracetam monotherapy showed no significant changes in TSH or fT4 levels and no cases of subclinical hypothyroidism.

Conclusions:

• Levetiracetam monotherapy appears to be safe regarding thyroid function in pediatric epilepsy patients.
• Valproate and, to a lesser extent, phenobarbital and carbamazepine may pose a risk for thyroid dysfunction in children.
• Routine thyroid function monitoring is recommended for children on certain ASMs, particularly valproate.