Oxycontin Oc 40 mg : OxyContin 40 mg tablets contain oxycodone hydrochloride. Oxycodone belongs to a group of medicines called opioid analgesics. OxyContin tablets are used to relieve severe pain when other forms of treatment have failed or are otherwise inappropriate to provide sufficient management of pain. Your doctor, however, may prescribe it for another purpose. Ask your doctor if you have any questions about why it has been prescribed for you. As with all strong painkillers, your body may become used to you taking OxyContin tablets. Taking it may result in physical dependence. Physical dependence means that you may experience withdrawal symptoms if you stop taking OxyContin tablets suddenly, so it is important to take it exactly as directed by your doctor.