My mother 55 years old , has schizophrenia for past 25 years ...She is not responding to any antipsychotic , i mean she responses initially but over time she stop responding. She has tried olanzapine , risperidon , amisulpride , haloperidol , clozapine (mixed and single doses with highest possible doses) ... currently she is taking amisulpride + clozapine + haloperidol (no response )... Which antipsychotic should be the next try with lesser side effects and higher efficacy ?