The Gale Encyclopedia of Medicine defines a pain reliever as "an analgesic medication that relieves pain without causing loss of consciousness." More than 76 million Americans have periods of chronic pain, according to the National Center for Health Statistics, requiring both over-the-counter (OTC) and prescription pain relievers. The U.S. Department of Health and Human Services reported in 2008 that nearly 30 percent of the population used some sort of OTC pain relief and almost 20 percent were prescribed a narcotic pain reliever each year.
Pain Types
Acute pain is a brief feeling from an identifiable cause. Chronic and recurrent pain is classified into four categories including nociceptive (ongoing tissue damage), neuropathic (linked with damage to the nerves, brain or spinal cord), mixed, or of undetermined causes. General pain relievers are only effective in treating pain related to ongoing tissue damage, according to the American Chronic Pain Association (ACPA).
OTC Pain Relief Drugs
Pain relievers are used "...to reduce or relieve headaches, sore muscles, arthritis or any number of aches and pains," according to the National Institutes of Health (NIH). Over-the-counter pain relievers, approved by the Food and Drug Administration (FDA) to be sold without a medical prescription, work by reducing the number of pain messages received by the brain and lowering body temperature. The FDA reports that "there are basically two types of OTC pain relievers: acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs)." NSAIDs include:ketoprofen, aspirin, ibuprofen and naproxen. Side effects of ongoing use of OTC pain relievers include abnormal liver function, gastrointestinal problems and an increase in blood pressure, according to the American Academy of Family Physicians (AAFP).
Opioid Pain Relievers
Opioid pain medications are manufactured from opium. These "change the way a person experiences pain," according to the FDA, by "attaching to a specific 'receptor' in the brain, spinal cord and gastrointestinal tract." Opioid medications include morphine, codeine, hydrocodone and oxycodone, which are sold under the brand names Oxycontin, Demerol and Vicodin. Medical prescriptions and monitoring are necessary when using opioid pain relievers. The side effects of this group of pain medications include risk of physical dependency, withdrawal symptoms in some individuals, and reduced effectiveness due to drug tolerance, according to the Mayo Clinic.
Combination Pain Relievers
When mild pain relief is not sufficient, doctors may prescribe a combination drug that incorporates an OTC medication with a prescription drug. A combination of Ibuprofen and diclofenac, classified as a mild to moderate pain reliever by the FDA, requires a prescription, as do hydrocodone and codeine when combined with acetaminophen. Pain relievers combined with other medications also assist in reducing severe coughs (codeine) and diarrhea (diphenoxylate), according to the National Institute of Drug Abuse.
