With all the meds he's on, and the fact that he's lost so much weight, and the trauma of this whole thing it sounds like a combination of things. Make sure he is absolutely well hydrated - this can really affect you mentally I mean off the deep end mentally. People don't realize it. It also sounds like he's super sensitive to treatment, which means he is likely sensitive to other drugs, particularly pain meds. Everyone responds differently to things. For example I have never seen the pleasure in Oxy. Codeine made me throw up, morphine or hydromorph gave me weird dreams but didn`t kill the pain post op, and Oxy didn`t kill the pain either but it put me to sleep like a baby. My friend`s husband turned into an energizer bunny nightmare while on it... she actually hid them. Definitely discuss it with the dr. it could be an electrolyte imbalance related to hydration and malnutrition or drugs. hugs...