Hi, Febrile seizure - causes sudden rise of temp, associated with (URI) upper respiratory Infection or viral infection and associated high temp. Sudden rise of temp, irritating the temp controlling center in the brain called Hypothalmus is the main cause of seizure. usually it is not associated with long low grade temp. Genetically some children may have low seizure threshold. Verify your child s vaccination chart and find out whether all vaccines are given. When the temperature has come down, nothing to worry. Treatment of the primary cause for the temp, is what is needed now. The dr treating your child has prescribed proper medicines. Regarding the anti-epileptic drugs, how long to take - follow your dr s advise. Always don t allow your child to get high temp suddenly. Before consulting a dr for temp. give anti pyretic and cold sponging (prevention is better than cure). Over all your child s problem is nothing to worry. best wishes