What Causes Panic Attacks When Drunk?

My son is on Pristiq and celebrated his 21st last night with friends, getting himself extremely drunk. He just called me, having a panic attack, because he had a vivid dark dream and doesn t feel like he has woken properly from the dream. He said he is still inebriated. Is this dangerous enough for me to insist that he goes to hospital? He is prone to panic attacks at times like this. I got him to breathe deeply while we were talking and told him to get as much water into himself as he can, and also food if he can face it. He doesn t want me to go to him (he is in a local hotel, having booked a room for a couple of nights - he is there with his girlfriend) but was scared that he may never come out of this dream-like state. I think he will once the alcohol dissipates. I would appreciate your advice.