What Causes Speech Difficulties After Taking Oxetol And Levipil?

my daughter is taking oxetol. but siezure did not stop.doctor prescribe levipil. so now she is taking both because doc told to take both for 2-3 months .then oxetol will be stopped slowly..my question is- she has some problem with speech and understanding sentences some time. is this the effect of taking both medicine.her siezure started only 2 yr ago .now she is 22