Carbamazepine serum thyroxine

Endocrine The effects of long-term carbamazepine ( = 18) and valproate ( = 14) on thyroid function in newly diagnosed children with epilepsy have been evaluated in a prospective open comparison with 32 sex- and age-matched controls [78. At baseline evaluation, thyroid function was normal. At the 3rd, 6th, and 12th month evaluations, patients taking carbamazepine had serum thyroxine (T4) and free thyroxine (fT4) concentrations significantly lower than baseline and control subjects valproate had no such effect. 

In a prospective, randomized study of thyroid function in 160 men and women with epilepsy both before and after double-blind withdrawal of antiepileptic drug monotherapy, serum samples were obtained from 130 [79 ]. After drug withdrawal, there were significant increases in free thyroxine serum concentrations in those who had taken carbamazepine. 

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