اثر داروهای ضد تشنج بر روی تستهای عملکرد تیروئید

Thyroid hormones have critical role in growth and development. Many factors including anti-convulsant drugs affect thyroid hormones. Anti-convulsant drugs are used commonly in children due to high prevalence of seizure disorders in this age group. In order to evaluate thyroid function tests correctly in these children understanding of drug effects is necessary. In this study، thyroid function tests of 55 anti convulsant drugs recipients with mean age of 8.88±3.9 year are compared with tests of age and sex matched control group including 42 non drug recipient normal children. Hypothalamic-pituitary axis was assessed with TRH test in 19 patients. Serum T4 level of patients were significantly lower than those of control group (p=0.005). Serum levels of TSH، T3، T3RUand FT4I had no significant difference between the two groups and all of the patients were clinically euthyroid. Hypothalamic-pituitary axis was intact in all of TRH tested patients. In children receiving anticonvulsant drugs the serum TSH level is a good indicator of true thyroid function rather than T4 level.