How do you get past a friend's denial and anger when you tell them they have a drinking problem and be ok?

I have a friend who has always drank socially with me when we were in undergrad. The thing is I've moved past that whole lifestyle and she's increased her habit to where she is going out everyday.

I've told her a few times but each time she denies she has a problem and gets pissed off to the point she won't talk to me for a few weeks. I don't know what to do. I know she needs help but I don't think anyone else realizes how often she does this. Is it time for an intervention?