© catherine delphiaApproved Drugs for Opioid Use DisorderWhile it might appear counterproductive, some drugs utilized to deal with opioid use disorder (OUD) trigger opioid receptors in the brain. Methadone is a full opioid agonist, binding to and activating opioid receptors while blocking the binding of other opioids. It is an opioid antagonist that knocks opioid molecules off the opioid receptors and takes their location.