Levorphanol

Levorphanol /lɛvaʊrfɑːnɒl/ (brand name Levo-Dromoran) is an opioid medication used to treat moderate to severe pain. Chemically, it is (−)-3-hydroxy-N-methyl-morphinan. It is the levorotatory stereoisomer of racemorphan, first described in Germany in 1948 as an orally-active morphine-like analgesic. It has been in clinical use in the U.S. since 1953.