1881

Grimaux prepares codeine by methylation of morphine: “Codeine possesses the same pharmacological actions as morphine, but is less potent. . . about 10 percent of administered codeine undergoes O-demethylation to morphine, and the resulting analgesic effect is primarily due to this conversion.” Codeine first isolated from opium by Robiquet in 1833 (Schiff, 192).