Oxycodone is a prescription drug which is also known as a narcotic. The drug is prescribed to be taken for the treatment of moderate to severe pain. When a patient takes the drug, it changes the brain senses and reacts to the pain. The drug travels to the brain and connects itself to opioid receptors. The drug causes a feeling of euphoria, one of the side effects of Oxycodone, when it is taken in higher doses. The drug also depresses the central nervous system and causes respiration.