Risk assessment of folic acid supplementation in phenytoin-treated epileptic patients: A pilot study

Abstract

Background:There have been studies that report clinical benefits of the use of folic acid as an adjuvant to the antiepileptic therapy in the prevention of antiepileptic drug-induced gingival enlargement. However, studies conducted in the past have also reported precipitation of epileptic attacks in patients on folic acid adjuvant therapy due to fall in sera levels of phenytoin due to drug interactions. The study was planned to investigate the association of phenytoin-induced gingival enlargement and sera levels of folic acid in epileptic patients on phenytoin therapy. Subjects and Methods: A total of 25 patients aged between 18 and 50 years clinically diagnosed with epilepsy prior to the start of phenytoin therapy were included based on selection criteria and written informed consents were obtained. Assessment of serum folic acid levels and gingival enlargement was done prior to the start of and after 6 months of phenytoin therapy. The statistical analysis was done using t-test and the baseline serum folate levels and the serum folate levels obtained after 6 months of phenytoin therapy were correlated with the respective grades of gingival enlargement using Pearson's coefficient formula. Results: The results of the study confirmed a significant association between low serum folate levels with increasing severity as well as an early onset of phenytoin-induced gingival enlargement justifying the judicious use of folate supplementation to prevent this inadvertent side effect of phenytoin administration. Conclusions: The results of the study suggest a higher incidence of gingival enlargement in phenytoin-treated epileptic patients with a positive correlation with falling serum folic acid levels as the duration of the therapy increases.