What are the causes of fluctuation in phenytoin levels when taking meds as prescribed?

I have already done as you suggested and no definitive answer, This site just keeps telling me about diabetes. I know about the diabetes part of it but ra;ther than explain the dialntin or the phenytoin or any of the other drugs they tune into glucose but do not say that is the cause. Still looking for the answer or answers.

meanmoz, there are times when the liver simply doesn't utilize dilantin as it should. I also take dilantin, as well as lamictal and klonopin, but on the occasions I've had seizures, my dilantin level is always low-even though I'm strictly compliant with it and am on a high dose... 500mg total daily dose. One Dr. mentioned to me that he thought, as I noted above, my liver simply didn't utilize dilantin as it should, and he was going to discontinue it. I asked him not to just because I feel a bit safer while taking it. This may not answer your question, or be helpful, but it could be nothing more than that.

meanmoz, I failed to ad that my dilantin level also gets too high rarely, and I have symptoms that I can usually quickly notice when that's the case... double vision and some other things. Just an FYI

Thank you for your information. Now I know my husband does not stand alone. He has been accused of being non compliant when I give him his medications on time every time. If you know where to find documentation according to this information it would be appreciated.

Mean Moz