Mom 64 cancer adv; has started to drink beer daily and "spice". I've tried P.A.R, after 72 hours she left. What can I do?

How much beer does she drink? I wouldn't worry about the spice. The jury is out on it, but it doesn't seem much more harmful than marijuana. In many states, medical marijuana is legal for people going through chemo or having some other medical problems.

I don't know about your sons. If they are recreational users it is one thing. But some people are problem users of things that get them high. You have to use your best judgment on that one. Are they living in AZ or FL?

Concentrate on helping your sons break the addiction. It may be too late for mom.
Best of luck

Inasmuch as drinking & using is not a good idea, I would say let your mom do whatever she please. She has an advanced cancer after all, how much do you think she's left? Apparently she's trying to deal with her condition *(I think). Again, she's an adult and is responsible for her own actions. You being a POA doesn't give you a right to tell her what to do. Oh well. Maybe legally you can, but leave it well alone.