A PHARMACOLOGICAL COMPARISON OF THE OPTICAL ISOMERS OF 5-ETHYL-5-PHENYL HYDANTOIN (NIRVANOL) AND OF 3-METHYL-5-ETHYL-PHENYL HYDANTOIN (MESANTOIN)

¹ Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina

The levorotatory isomers of 5-ethyl-5-phenyl hydantoin (Nirvanol) and of 3-methyl-5-ethyl-5-phenyl hydantoin (Mesantoin) are more active as anesthetics in mice than are their respective antipodes.

l-Nirvanol anesthetizes mice in lower dosage than does the corresponding Mesantoin isomer.

d-Kirvanol disappears from the plasma of the rat much more rapidly than does l- and produces a briefer anesthesia in mice than does l-.

l-Mesantoin is demethylated by the rat at a greater rate than is its isomer.

Species differences in the physiological disposition of Nirvanol and Mesantoin are discussed.