How Folic Acid interacts with Anticonvulsants

Interaction type: Depletions

Interaction rating: Study Supported

Anticonvulsants are reported to decrease levels of folic acid in the body. Supplementation with the affected nutrient may be necessary, but if you are using any of these medications please see your healthcare professional before taking a folic acid supplement. (1) (2) (3) (4) (5)

These drugs include phenytoin, carbamazepine, primidone, gabapentin, valproic acid, felbamate, lamotrigine, mephenytoin, fosphenytoin, clonazepam, ethosuximide, diazepam, clorazepate dipotassium, levatiracetam, tiagabine, topiramate, methsuximide, phensuximide, trimethadione, magnesium sulfate, acetazolamide, oxcarbazepine, zonisamide, ethotoin


  1. View Abstract: Kishi T, et al. Mechanism for Reduction of Serum Folate by Antiepileptic Drugs during Prolonged Therapy. J Neurol Sci. Jan1997;145(1):109-12.
  2. View Abstract: Carl GF, et al. Phenytoin-folate Interactions: Differing Effects of the Sodium Salt and the Free Acid of Phenytoin. Epilepsia. Apr1992;33(2):372-75.
  3. View Abstract: Carl GF, et al. Effect of Chronic Primidone Treatment on Folate-dependent One-carbon Metabolism in the Rat. Biochem Pharmacol. Jul1987;36(13):2139-44.
  4. View Abstract: Hendel J, et al. The Effects of Carbamazepine and Valproate on Folate Metabolism in Man. Acta Neurol Scand. Apr1984;69(4):226-31.
  5. View Abstract: Seligmann H, Potasman I, Weller B, et al. Phenytoin-folic acid interaction: a lesson to be learned. Clin Neuropharmacol. Sep1999;22(5):268-72.