“I'm concerned about how much my brother drinks. Is there anything I can do?”

First, talk to him about your concern and be specific, list examples of behavior that worries or concerns you. You may mention that he should talk about his drinking with a professional, such as an alcoholism counselor. Or ask him to go to to an AA meeting with you and see what he thinks (an open meeting). Do not be confrontive because that is likely to turn him off. Just discuss your concerns and be specific with examples and then advise him to get some type of assessment from a a professional.

Thank you for your bravery and empathy to reach out for help. You can stay non-judgmental and resolves to help him. Hopefully, he can acknowledge he has an alcohol problem.
One very good and simple screen tool is CAGE:

C- Have you tried to CONTROL your drinking and been unable to?
A- Have others been ANGRY with you about your drinking?
G- Have you felt GUILTY about your drinking?
E- Have you ever needed an EYEOPENER?

Score yes=1, no=0
If the total score is more than 1, there is a problem with alcohol drinking, and seeking help is appropriate. If he has a primary care physician, that doctor can help. If employed, many employers human resource department can assist. If he has healthcare insurance, that company can assist in seeking help, and many communities have Alcoholics Anonymous and Al-Anom group meetings which can be resources for help.

Serenity, Courage, Wisdom,

Doc S.