question: Hello doctor, I recently tried switching medicines from Phenytoin to Briviact. Last night, was the first time I tried it. I am transitioning off the Phenytoin. I became dizzy, disoriented and felt very weird. I have not had a seizure in the last 9 years. But, I was not ready to go off the medicines, since I do a lot of traveling. My neurologist recommended to try a new medication with less side effects. Is this a common experience while switching Phenytoin to Briviact? I took it last night at 9.30 and I am still feeling out of it and irritable. I have never had this side effect from the Phenytoin.