Effects of Phenobarbital Monotherapy on Thyroid Function Tests in Epileptic Children


To determine the effects of Phenobarbital (PBT) monotherapy on thyroid function tests including total T4, total T3 and TSH in epileptic children whose age ranged between 7-15 years. The study was conducted in the department of pharmacology, college of medicine, university of Mosul, during a period of 9 months commencing from January-2005. The patients’ group consist of 19 patients on PBT monotherapy together with a control group. Serum total T4, total T3 and TSH concentrations in epileptic children on PBT monotherapy were compared with those in control group by using unpaired “t” test. We found a statistically significant reduction in total T4 levels in patients receiving PBT compared with the control group, while Total T3 and TSH levels were indifferent statistically. All patients were in euthyroid state, there were no clinical findings of hypothyroidism. These data suggest that PBT monotherapy decreases serum total T 4 levels significantly(P<0.001), while total T 3 and TSH levels remained unaffected