Uses: This medication is used to help relieve moderate to severe ongoing pain (such as due to cancer). Oxycodone belongs to a class of drugs known as narcotic (opiate) analgesics. It works in the brain to change how your body feels and responds to pain. Do not use the sustained-action 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.