I dont think I've ever heard on one becoming tolarent to Lamicatal, Maybe I read that wrong. I've been on Lamictal for about 5 yrs now and have no intensions of ever going off. It has been the best medication I've used so far. A few "additions" every now and then but they all have been short term and have always stayed on Lamictal. Not personally familar with topamax so I cant really comment there.