To be in a hyper/drunken state caused by having a Four Loko.
Zack: You were loko last night.
Dom: Yeah, I had my first Four Loko and can't remember anything.
Zack: All you were doing was running around being drunk and trying to get with all the sorostitutes.
to go crazy after a member of the opposite sex, and completely change your personality and outlook on life, like Jhon Lennon did for Yoko. Often includes completely ruining a planed event, or sometimes ignoring friends for weeks.
"dude where is Ben, i thought he was coming to the barbeque off."
"Didn't you hear, he went all loko on us, he turned into a vegan"