Isoflurane anesthesia is stereoselective.

The anesthetic effects of the (+) and (-) isomers of isoflurane were determined in mice. Like the clinically important racemate, both isomers produced dose-dependent increases in anesthetic sleep time. A statistically significant (P less than 0.005, ANOVA) difference in the potencies of these isomers ((+) greater than (-)) was observed. To our knowledge, this is the first demonstration of a stereospecific action of a volatile anesthetic in vivo.