My doctor does blood testing once in awhile for the Trileptal, the only thing that really has to be watched for is sodium levels because it can cause them get too low which is not good. She does this maybe 2 or 3 times a year, more if I need my dose adjusted. I had previously been on Depakote and then Lithium before that. Out of the 3 I've had the least issues with Trileptal and it has been helpful.