I know I sound like a cracked record, but the answer to drink-fuelled violence is to start with education in schools and get the message across that alcohol poisoning (and drop the trendy labels like trollied, hammered, mullered, and all that nonsense) is not the definition of a good time.
Unlesss young people can be turned away from the need to drink to excess to fulfil the cultural attitudes towards 'a good time', we will never stop this anti-socail behaviour.
Of course, education costs money, and its not sexy, so don't expect any government any time soon to start the process off.