My Cousin Has Been On Chemo, Azacitidine And Anti Nausea

My cousin has been on chemo, azacitidine and anti nausea drug granisetron this year for CML, 5 days a week then 3 week gap. He is manic, delightful, but doing crazy things moneywise and personally which we are concerned may have long term repercussions. We have asked his doctor if there is anything in these drugs which would precipitate this response and he has said no and that he has psychiatric problems. We can't accept this as this strange behaviour has only been since the chemo treatments this year. He settles down about a week before his treatment and then it comes back when he is treated again.