I have read it is a comparatively new drug so maybe long term side effects are not known .It may be best if you speak to his doctor for information ..good luck
He has been on Keppra for about 2 years now. He's tolerating it well with no problems. I'm not sure for how long since he has other medical issues and this is just for maintenance to prevent seizures.
How long has he been taking it, does his doctor tell you how long he will need to take it, there are side effects ,how does he tolerate it ?