Wiktionary
levopropoxyphene
n. (context pharmaceutical drug English) A particular narcotic antitussive.
Wikipedia
Levopropoxyphene
Levopropoxyphene is an antitussive. It is an optical isomer of dextropropoxyphene. The racemic mixture is called propoxyphene. Only the dextro-isomer (dextropropoxyphene) has an analgesic effect; the levo-isomer appears to exert only an antitussive effect. It was formerly marketed in the U.S. by Eli Lilly under the tradename Novrad (a reversal of Darvon) as an antitussive.