Animazine was a stimulant used to keep a person awake.

In 2374, The Doctor recommended giving large doses of animazine to the crew of the USS Voyager to keep them awake. He gave Commander Chakotay an animazine derivative to use to stay awake, but Chakotay instead used it on a member of the dream species who were affecting the Voyager crew. (VOY: "Waking Moments")