Folic Acid

[FrankiesGram]

Hi everyone, I have been on Dilantin 300mg. for 30 years, with excellent results.  During that time I have had only one breakthrough seizure, and that was 18 years ago.  My question regards folic acid.  I have done some research and found that dilantin can lower folic acid levels, but I have also read that folic acid can interfere with dilantin, lowering the blood level, and setting one up for a possible breakthrough seizure.  I recently purchased folic acid supplements because I thought it would be a good idea to take them, but now I am not so sure.  The supplements I have are 800 mcg.  Thank you for any help with this.

[FrankiesGram]

Thank you very much, Doctor, for your reply.

[Abhijeet Deshmukh, MD]

Hello.

You have correctly interpreted your research on the topic. And this article does say the same.

http://www.ncbi.nlm.nih.gov/pubmed/8520091

It says, "...Serum folate decreases when phenytoin therapy is initiated alone with no folate supplementation. Folic acid supplementation in folate-deficient patients with epilepsy changes the pharmacokinetics of phenytoin, usually leading to lower serum phenytoin concentrations and possible seizure breakthrough..."

It however says that initiation of Folic acid and phenytoin together is beneficial.
Since you can't go back and start all over again, you can take a small dose. It has been observed that as los as 1mg dose can perturb phenytoin’s levels, You may take doses lower than 1mg/day.

Regards