Until my recent pregnancy, I had been taking clonipin for seizures for at least 5 years. I didn't have any severe side effects, and it worked well with my other seizure medications (carbatrol and neurontin) to cut down on the number of seizures I was having. In fact, I had been seizure-free for several months, although since I had to quit taking it I have had some tiny ones.
My daughter takes clonapin, we give it to her when she starts to seize and it sometimes brings her out of it, or they are not as bad, We have had good luck with it. Yes there are side effects but, they all have them.