My daughter was on Keppra ( levetiracetam) for seizures, and when a generic became available the insurance company required we switch to the generic. Soon after starting the new generic, she basically passed out in the car. She was responsive but heavily sedated. Clearly she had overdosed on levetiracetam, even though she received the same prescribed dose as before. We were able to get her back on Keppra, but that was a scary experience.