Heroin breaks down into codeine and morphine. Codeine breaks down into
morphine. The opiate drug tests look for codeine,
morphine, and 6-acetyl-
morphine. The presence of 6-acetyl-morphine is relatively conclusive of recent heroin use, but is only detectable for a few hours after use. The presence of codeine can be the result of either heroin or codeine use. The presence of morphine can be the result of the use of heroin, codeine, or morphine.