Eterobarb (Antilon) is a barbiturate derivative. It is an effective anticonvulsant as demonstrated in animal and clinical studies. Eterobarb possesses a unique and clinically intriguing feature-at therapeutically effective blood levels, the hypnotic side effects usually associated with barbiturates appear absent. Though effective against both electrically and chemically induced seizures in mice and rats, virtually no hypnotic effects were noted except at lethal doses. Double-blind cross-over studies have confirmed the anticonvulsant efficacy of eterobarb and several phase II and phase Ill studies show eterobarb to be an effective anticonvulsant with less hypnotic activity when compared with phenobarbital. Eterobarb had been NDA filed for the treatment of epilepsy in the US, UK, Switzerland and Canada. However, this research has been discontinued. The compound was originated by Colgate Palmolive, then licensed to MacroChem.