CASA want to know, hence it's amongst the questions your doc will ask you in your class 1 renewal.
If it's just a once off, not a pattern of behaviour, it won't impinge on your career significantly. At previous employer one pilot confessed to a DUI charge to the Chief Pilot (necessary) and was told that put him in the majority at that (NT) operation. Said pilots now flying 737s, 767s, A330s and E-Jets.