(American) Excited or agitated. This term from black street slang, which can also indicate excited anticipation, may derive from an ampoule (of a narcotic) or from 'amphetamine(d)', but is equally likely to derive from the musicians' jargon 'amped-up', meaning with the amplifiers fully rigged.

'While they were keeping me waiting I was getting more and more amped up…' (Recorded, musician, New York City, 1995)