If my mother -- who is suffering from cancer -- starts lying to me, stealing from me, and generally putting my safety at risk, then I will withhold my support from her and put up a boundary miles high -- just as I had to do with my partner when he did these things and put me at risk due to his addiction.
It's interesting that you quote the government agency called the National Institute of Health -- but at the same time you ignore the fact that this same exact government which the National Institute of Health is a part of finds it necessary to fire people due to drug use, to prevent people from driving due to drug use, to incarcerate millions for drug use, even take away children from their families due to drug use.
Odd paradox, isn't it? One little government agency talks about chronic, relapsing brain disease, and tells us to be compassionate for the poor poor sufferers of drg addiction -- and some people on this board take that as the gospel straight from God! But on the other, many governmental departments and agencies take a very, very hard line. Just try getting caught shooting up or dealing drugs if you have a security clearance job and see how far you get. Your career would be ruined.
The government very sensibly protects itself. It's perfectly ok for anyone who is dealing with an addict to take steps to protect themselves -- without remorse or guilt.