Oxycodone is used to relieve moderate to severe pain. Oxycodone extended-release tablets and extended-release capsules are used to relieve severe pain in people who are expected to need pain medication around the clock for a long time and who cannot be treated with other medications. Oxycodone extended-release tablets and extended-release capsules should not be used to treat pain that can be controlled by medication that is taken as needed. Oxycodone extended-release tablets, extended-release capsules, and concentrated solution should only be used to treat people who are tolerant (used to the effects of the medication) to opioid medications because they have taken this type of medication for at least one week. Oxycodone is in a class of medications called opiate (narcotic) analgesics. It works by changing the way the brain and nervous system respond to pain.