What wrong with my Grandma? Please help, I'm worried!?

Ok, my Grandma is 72 years old. She has been taking a lot of pain medication for the past month or so because she had back surgery. She recently (Saturday) was diagnosed with a UTI. She is now taking an antibiotic and several pain killers (Darvaset, Tylenol 4). She has been taking the antibiotic for 4 days. Today, she started talking crazy, almost like she was dreaming and awake. She is in the hospitol now. She was trying to eat her blankets saying it is chicken. Also, she was thinking that she was a bear. Also, my mom asked her "Do you even know where you are?" and she replie "What are you talking about, you can't afford a maid!". I'm serious, I'm not joking. She usually doesn't have probelms wtih the painkillers. I'm thinking it was a reaction between the painkillers and the antibiotic. They gave her a sedative in the hosp and it made it worse. You cant talk to her. If you say something to her, she will sort of look through you but not at you. It's almost lik eshe having dreams but awake. Do you guys have any idea? This came out of no where, she has never acted like this before (sxcept one time she was on morphine- shes' allergic to it), and she has no other problems- no tumor in bran, no blood problems, no stroke or aything. What the heck is happening to her? Please help, Thanks.