Opioids are commonly prescribed because of their effective analgesic, or pain-relieving, properties. Medications that fall within this class sometimes referred to as narcotics include morphine, codeine, and related drugs. Morphine, for example, is often used before or after surgery to alleviate severe pain. Codeine, because it is less efficacious than morphine, is used for milder pain. Other examples of opioids that can be prescribed to alleviate pain include oxycodone ( OxyContin ), propoxyphene (Darvon), hydrocodone (Vicodin), and hydromorphone (Dilaudid), as well as meperidine
(Demerol), which is used less often because of its side effects. In addition to their pain – relieving properties, some of these drugs for example, codeine and diphenoxylate (Lomotil) can be used to relieve coughs and diarrhea.