Cylanite was a lethal poison that attacked the victim's nervous system, affecting a victim's coordination.
In reference stardate 2/1412 (circa 2273), an Orion slave girl working as an assassin on the Orion Colony world of Daros IV used a dagger coated with Cylanite to attack her victim, though it was only effective once. (FASA RPG module: Orion Ruse)