Oxycontin. The strong narcotic pain reliever is similar to morphine and is designed to treat moderate to severe pain expected to last for a long time. It should be used on a regular schedule as prescribed by a doctor, not on an as-needed basis. Side effects can include nausea, vomiting, constipation, mild itching, drowsiness, dry mouth, lightheadedness, loss of appetite and weakness. Oxycontin is a highly addictive drug.
