Well if his drinking is affecting your life, I would suggest alanon and some healthy boundaries. I don't allow active addicts or alcoholics into my home. I don't do things for people they can do for themselves. If someone I know is driving drunk, I'll call the cops. I'm not taking part in anyone else's addiction. If he wanted to get sober, there's many resources for that.. and so far you've not mentioned that you're an addictions psychologist or a treatment center. Detachment with love. You're protecting him from reaching his 'bottom' whatever that might be.. and loving him to death.
Just my .02.. I've sat on all sides of this fence.