Sonambutril was a strong sedative used for medical purposes. It was in use during the mid-22nd century. The chemical name is derived from the latin "somnus," meaning "sleep."

When Hoshi Sato and Trip Tucker caught a strain of a silicon-based virus, Phlox ordered them to use sonambutril after Sato was able to escape confinement. The sedative was able to knock out both officers for a long period of time. (ENT: "Observer Effect")