Good morning @greff . Here is a link to an article about the use of curcumin: https://alzheimersnewstoday.com/curcumin-plant-extract-possible-alzheimers-treatment/
You will notice that it is only in early research stages.
As for donazapil, it will help with managing some symptoms, but cannot alter or reverse the disease. AD is a terrible disease but researchers are working hard to find an answer. Your doctor is right, donazapil had side effects which is why they start on a low dose and slowly work up. This can help minimize side effects. I wish you the best in caring for your wife.