Are There Any Side Effects Of Taking Tegretol While Taking Gabapentin?

I'm really struggling with answers to diet problems I'm having. When I was 12 I started having seizures, went on tegretol and things were fine. I went off medication 3 years ago, started having restless leg syndrome and was put on gabapentin.Ever time I eat something with sugar I feel extremely drunk, have gone into coma state. I got blood work for diabetes and things came back fine, I had a burrito last night with brownie and can't seem to get out of this drunken state. I wanted to go back on tegretol which I did, few days ago, I'm really scared, my neurologist said it was ok to combine medications.