Levallorphan is a synthetic opioid antagonist drug used to reverse the effects of opioids and to treat opioid dependence. There are a few synonyms for Levallorphan, including dromoran, lorfan, nalorphinan, and 17-methylnorphinan-3-ol. Like Levallorphan, dromoran is also an opioid antagonist drug used for its anti-analgesic effect. Lorfan is another synthetic opioid antagonist that is used to block the effects of opioids and is also used in the treatment of opioid dependence. Nalorphinan is a potent opioid antagonist that is used to treat opioid dependence and can also help reduce the severity of opioid withdrawal symptoms. Finally, 17-methylnorphinan-3-ol is another synthetic opioid antagonist primarily used to treat opioid addiction.