Being merciful and helping another person, or even an animal, is a great mitzvah. It was perhaps the most pronounced trait of the founder of the Jewish People — Abraham, and we, as his descendants, are taught that we have “inherited” this trait. A different Abraham, Abraham Lincoln, observed: “I have always found that mercy bears richer fruits than strict justice.”
Therefore, I have no doubt that the right thing to do would be to treat your troubled relative in as merciful a way as possible. The question is, what does that mean in a practical manner in your particular situation?
One should also keep in mind the teaching of our Sages: One should not show mercy to someone who does not have “de’ah”. The word de’ah is usually translated as wisdom or knowledge, but in this sense means that the person who would be the recipient of the mercy is not able to make rational and good decisions. For example, a person who gives money to an alcoholic on the street might feel that it’s a positive thing to do, but in fact it might be a destructive and negative thing to do since the alcoholic will virtually certainly take the money and buy more alcoholic drinks — which will make his situation worse, not better.
Therefore, I suggest the follow course of action: If the money that you give goes directly to his doctor (or the bill collector), then it is a great mitzvah to help your relative as needed and as your means permit. On the other hand, if your relative demands that you give him the money and that he will pay the doctor (and his other bills), then I think that you would be better off not helping him, since he would probably just use the money to buy alcohol instead of paying for his real needs.
In summary, although it is absolutely true that your relative has squandered both his money and his life away with his drinking, that does not mean that you should not help him if you can do so in a way that does not feed his addiction.
I wish your relative a speedy and complete recovery.
