<unk> s are drugs that act as central nervous system depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedation to anesthesia.  Some are also used as anticonvulsants.<unk> s are derivatives of<unk> ituric acid.
Barbiturate
Enflurane
Isoflurane
Methoxyflurane
Desflurane
Methanol
Anethole
Halothane