Sure, but the doctor doesn't have to do much research in this case. This is front-page news in the NY Times. And about "every single medication": this is the only approved medication to delay clinical decline due to Alzheimer's. And there are only a few medications to treat symptoms.

I know this isn't a perfect world, but it doesn't seem to be asking a lot for a doctor to know this. (Especially for a drug that currently costs $56K/year and presumably will cost more next year.)