I was on it for a month. To be fair, this was the first med they tried right after my official diagnosis, and here's the scenario: I'm not "allergic" to it as much as I am "intolerant". They started me at 2000 mg/day but kept increasing the dosage because of breakthough auras until I was on 4000 mg/day. I had problems with thirst, balance, memory, fatigue, double-vision, wordlessness, working with numbers, judgement, "Kepp-rage" (hair-trigger aggressiveness) and there was no break from the intense intoxication.

After three weeks I began with suicidal ideation, but at 4000 mg/day I felt I was being poorly managed. They immediately hospitalized me, immediately cut the Keppra in half, but infused me, by IV, with a full dose of Dilantin. I don't tolerate Dilantin either. I barely got to the car after discharge because just looking down at the geometrically arranged floor tiles in the exit hallway made me so dizzy and nauseated that I needed a wheelchair. It was worse than when I was admitted.

Because of their cavalier approach, I fired that neuro team and went with an epileptologist at a different hospital facility, who agreed that I was grossly overmedicated, but eventually straightened me out. It took him months to wean me off those meds, at which time he started me on the Lamotrigine. It's been very much more tolerable, no seizures for 5 years now.

I'm sure dosages were the biggest contributors to my intolerance symptoms, as a result of their assembly-line approach to their patients, to just dump them full of meds until they have no reliable judgement, then insist on surgery. I agreed to the surgery, terrified, until the epileptologist said, "Why don't we just try to control the seizures first before we talk about surgery?" I guess credentials aren't as important as expertise. He ended my nightmare.

Hi there, I was on Keppra for a week. Very recently, last week and reacted very badly.
I was dizzy all the time, very wobbly when I walked (needed to hold onto something), I couldn't find words, excessive thirst, exhausted all the time, absolutely no appetite and no seizure control.

Fatigue was pretty severe the first few days after starting it. I would 'nap' until 1 or 2 in the afternoon. Then it started getting less and less

Slight fatigue and naps now and then