Shoot Up Meaning

(intransitive) or (transitive) To inject (a drug) intravenously.

Example: Used other than as an idiom. To shoot upwards.
1899, Stephen Crane, chapter 1, Twelve O'Clock:
  There was some laughter, and Roddle was left free to expand his ideas on the periodic visits of cowboys to the town. “Mason Rickets, he had ten big punkins a-sittin' in front of his store, an' them fellers from the Upside-down-F ranch shot 'em up […].”