Given your description of your brother's drinking habits I'd say there's a definite possibility he's an alcoholic. It's good you draw attention to his excessive drinking...& realize that nothing bad has happened YET. Most alcoholics have to hit their own bottom before admitting they have a serious problem with alcohol. It sounds like you're doing all you can to try to spare him the "yets." Other than that, I don't know what else you can do. Perhaps a family intervention might help?