Codeine, fentanyl, morphine, oxycodone and tramadol are narcotic pain medications. Vicodin, Demerol and Dilaudid are also pain medications, according to MedlinePlus. Narcotics work by binding to brain receptors, therefore blocking pain.
Due to the abusive and addictive aspects of pain medications, narcotics are typically only used for those in severe pain who have not found relief from any other sources, says MedlinePlus.
Narcotic medications do not work on the pain source like nonsteroidal anti-inflammatory drugs. Instead, they only suppress it. Narcotic pain medications have many side effects, including itching, vomiting, constipation, weakness and dry mouth, claims Health.com. Respiratory distress, drowsiness, confusion, urination difficulties and nausea are also side effects.