OxyContin (oxycodone) is a narcotic pain reliever similar to morphine. OxyContin is used to treat moderate to severe pain that is expected to last for an extended period of time. OxyContin is used for around-the-clock treatment of pain. Oxycodone is not for treating pain just after a surgery unless you were already taking oxycodone before the surgery. OxyContin may also be used for purposes not listed in this medication guide.