Can Kepra And Lamictal Be Prescribed By One Doctor?

I had a brain tumour 20 years ago - was been placed on Kepra. I was having petit mal seizures, apologize for the spelling. I was also put on Lamictal. I am still taking both medications. I take Kepra with a presciption ordered by my neurologist and Lamictal ordered by my epilepsy physician. I was wondering why take these under two different doctors? I m a little embarassed to approach my doctor with this question now. Any information would be appreciated