Its phenolas bitone - aka phenobarbitol poisoning phenobarbital (phe·no·bar·bi·tal) (fe”no-bahr´bĭ-təl) [USP] a long- acting barbiturate, used as a sedative, hypnotic, and anticonvulsant, administered orally. p. sodium [USP] the monosodium salt of phenobarbital, having the actions and uses of the base; administered orally, intravenously, intramuscularly, and subcutaneously. phenobarbitone (phe·no·bar·bi·tone) (fe”no-bahr´bĭ-tōn) phenobarbital.