Serum folate levels in children on long-term anti-seizure medication in a Nigerian tertiary center—Implications for practice and public health

BACKGROUND: Epilepsy is the most common childhood neurological disorder in Nigeria. Treatment of epilepsy is long-term and sometimes lifelong with anti-seizure medications. There are conflicting reports on the effect of anti-seizure medications on serum folate. There is therefore a need to determine the effect of a commonly used anti-seizure medication's on serum folate levels of children. This would provide an evidence-based consideration for folic acid supplementation in children on anti-seizure medication as has been suggested by some studies. STUDY OBJECTIVES: To determine whether serum folate levels were lower in children taking long-term carbamazepine or sodium valproate, compared to a control group. METHODS: Serum folic acid levels were measured from well-nourished children between the ages of 1–17 years on carbamazepine and sodium valproate monotherapy and their age/sex-matched controls, using spectrophotometry. RESULTS: The mean serum folate levels of patients on carbamazepine (43) and sodium valproate (22) were 0.032 mg/l ± 0.009 and 0.028 mg/l ± 0.008, respectively. The mean folate levels of the controls were 0.046 mg/l ± 0.03 (p = 0 001). No statistically significant difference was observed between the serum folate levels of children on the two anti-seizure medications, that is, carbamazepine and valproate. CONCLUSION: The children on treatment with carbamazepine and sodium valproate for more than 6 months had statistically significantly lower serum levels of folic acid compared to the standard reference range and controls. The serum folate levels of children on carbamazepine were not statistically different from those on sodium valproate.