Oxycodone is a semisynthetic opioid of formula C18H21NO4 that is derived from thebaine. It is a moderately potent opioid analgesic, generally used for relief of moderate to severe pain. It has a role as an opioid analgesic, a mu-opioid receptor agonist and an antitussive. It is an organic heteropentacyclic compound and a semisynthetic derivative. It is functionally related to a thebaine. It is a conjugate base of an oxycodone(1+). It derives from a hydride of a morphinan.