Suffering With Psychosis, Gets Drowsiness, Tiredness On Taking Clozapine. Prescribed Also With Joykem, Parkin. Right Medicines?

Hi Doctor! My brother is suffering from Psychosis . He has been advices to take Clozapine 100mg to 300mg. however, when we have administered him 100mg clozapine, he is not able to even do any activity for more than 5 minutes. he is drowsy, tired , does not even want to step out of house.. Another doctor on seeing these symptoms reduced the dosage to 50mg daily and added joykem & parkin 2mg to it. all these medicines have not cured him and seems have dangerous sideffects. Earlier Oleanzapine was been adminitered to him (before clozapine for nearly 5 years).Dr can you please advice as how much time dosuch patients take to be perfectly ok ? and whether these are right medications to be given?? The problem faced by patient is: Not been able to concentrate, to continue his course beyond 1 year, carry out daily work like bathing, brushing etc.,taking initiative, thinking maturely. He does not hallucinate or hear any voices. He does not want to talk also