Buy Oxycodone Online, Oxycodone is a semisynthetic derivative of codeine that acts as a narcotic analgesic more potent and addicting than codeine. An extend-release (ER) form of oxycodone (Xtampza ER) was approve for the management of daily, around-the-clock pain management in April, 2015. This medication is use to help relieve moderate to severe pain. Oxycodone belongs to a class of drugs know as opioid (narcotic) analgesics. It works in the brain to change how your body feels and responds to pain.