Severe seizures. Do if it occurs again?

My baby girl one year 8 months old. Morning she was active and playing. Evening she looked dull. Her temperature was 99. She screamed suddenly and got seizures. She had mild shivering. After seizures, She had body pain and was irritated. She vomited milk which was gvn bfr. After some time she got severe seizures. Her hands, eyes were severely twitching. There was much saliva coming out from her mouth. We gave midacip spray. Doctor prescribed valparin syrup, topomac and frisium daily due to seizures. Yesterday at night, after taking medicine, she vomited within half an hour. So dosage was repeated. But then too. She vomited. My question is why do these seizures occur even though she's on medication. Could it be the missed dosage or raised body temperature. What to do if it occurs again