Seizures becoming more frequent please help

Hi my 16 year old daughter went 10 months seizure free now she is having them 2x a week she is having a medicine change dr is weening her off keppra introduced vimpat she is on zonegran and acetazolamide.  I don't think vimpat is working dr said you have to wait for levels but we have to sit back and watch her suffer, please any help would be appreciated he said if  vimpat doesn't work maybe he would try  onfi or eslicarbazepine.