Phenobarbitol is a barbituric acid derivative that acts as a nonselective central nervous system depressant used to control epilepsy seizures and as a sedative to relieve anxiety. It is also used as a short-term treatment for insomnia. Phenobarbital is also known by other names, such as Barbita, Comizial, Gardenale, Fenilcal, Luminal, or Solfoton.