An opioid antagonist with properties similar to those of naloxone; in addition it also possesses some agonist properties. It should be used cautiously; levallorphan reverses severe opioid-induced respiratory depression but may exacerbate respiratory depression such as that induced by alcohol or other non-opioid central depressants. (From Martindale, The Extra Pharmacopoeia, 30th ed, p683) (en)
Levallorphan antagonizes opioid effects by competing for the same receptor sites. It binds to the opioid mu receptor and the nicotinic acetylcholine receptor alpha2/alpha3. (en)