Objective: To evaluate plasma homocysteine (Hcy) concentrations in children receiving sodium valproate (VPA) and carbamazepine (CBZ), monotherapy, in comparison with healthy control subjects and to determine the possible relationship between Hcy levels and dosage and plasma concentrations of the antiepileptic drugs.
Methods: We measured levels of fasting and post-methionine Hcy, plasma pyridoxal 5'-phosphate (PLP, active vitamin B6), serum folate, erythrocyte folate and serum vitamin B12 in 60 epileptic patients (29 females, 31 males), aged from 14.2 to 17.9 years, subdivided into two groups according to their therapy. Sixty-three healthy sex- and age-matched children served as controls. These measurements have been performed before the beginning of therapy and after 1 year of therapy with VPA or CBZ.
Results: Before the beginning of therapy, there were no significant differences in fasting and post-methionine Hcy, plasma PLP, serum folate, erythrocyte folate and serum vitamin B12 values between the control group and the two groups of epileptic children. After 1 year of therapy, patients treated with VPA and CBZ showed a significant increase of the plasma concentrations of Hcy when compared to baseline data and controls values. Moreover, was observed a significant decrease of serum folate and plasma PLP. On the contrary, serum vitamin B12 and erythrocyte folate levels remained in the normal range.
Conclusions: Our study demonstrates that prolonged treatment with VPA and CBZ increases plasma concentrations of Hcy.