Oxycodone is an opioid medication for moderate to severe pain. Its side effects may include constipation, dizziness, vomiting, and drowsiness. The elderly may be more sensitive to such side effects. One of the brand names is OxyContin; this medicine is usually taken orally and the onset of relief normally begins within 15 minutes and lasts for up to 6 hours. This has been abused as it may be habit forming.