FATHER HAS PARKINSON'S, ALZHEIMER'S - GETTING WORSE

My father was diagnosed with Parkinson's and Alzheimer's last year. He has been taking all the drugs the doctors have prescribed but he seems to be slowly getting worse any help would be greatly appreciated. The tremors are getting worse in his hands and leg and his dementia is getting worse from the Alzheimer's he spent 2 hours setting in the parking lot of the grocery store, he knew he was supposed to get groceries but couldn't remember what he was supposed to get and was too embarrassed to call anyone. I don't want my father slipping any further away from us, so any help would be great, it just seems like regular meds aren't working.

Thanks