This medication is used to help relieve severe ongoing pain (such as due to cancer). Oxycodone belongs to a class of drugs known as opioid (narcotic) analgesics. It works in the brain to change how your body feels and responds to pain. The higher strengths of this drug (more than 40 milligrams per tablet) should be used only if you have been regularly taking moderate to large amounts of an opioid pain medication. These strengths may cause overdose (even death) if taken by a person who has not been regularly taking opioids. Do not use the extended-release form of oxycodone to relieve pain that is mild or that will go away in a few days. This medication is not for occasional ("as needed") use.