Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Nonsteroidal drugs take their name from the class of compounds created to act as an anti-inflammatory and analgesic (painkiller). A steroid is a compound that may occur both in a natural form as well as through synthesis. Steroids are defined chemically as substances that possess 17 carbon atoms, arranged in a series of four rings. Many of the natural steroids are hormones, the chemicals that are involved in the control of many physical processes. The most notable of these steroid hormones are the male hormone testosterone, the female hormones estrogen and progesterone, vitamin D, and adrenalin. The naturally generated anti-inflammatory cortisone is also a steroid.

Anti-inflammatories are those agents that are intended to reduce the pain and swelling caused when a joint becomes irritated, often through overuse. Ice is a common treatment for an inflammation or swelling of a muscle tissue or joint. Nonsteroidal anti-inflammatory drugs (NSAIDs) also tend to reduce fever. NSAIDs function by neutralizing the cyclooxgenase (COX) enzyme that is produced at the site of a musculoskeletal injury. Enzymes are proteins that act as a catalyst in specific types of biological reactions; at the injury location, the COX enzyme will naturally generate inflammation. COX enzymes are present in the body in two forms, COX-1 and COX-2.

COX-1 is present in cells throughout the human body. It plays an important role in the regulation of the protection of the stomach lining, the regulation of salt and fluid balances, and the flow of blood to the kidneys. COX-2 is found primarily in the immune cells and the cells of the central nervous system (CNS). Each produces prostaglandins, the actual cause of inflammation and pain. NSAIDs function by inhibiting these enzymes that otherwise produce prostaglandins.

The most well-known of the NSAID class of medications is aspirin, or acetasalicylic acid, first synthesized in 1899. The history of this active ingredient of aspirin as an analgesic and as an anti-inflammatory is much longer. More than 3,000 years ago, the use of extract of the myrtle plant, which contains salicylic acid was used to relieve joint pain and inflammation. Willow bark, which also has salicylic acid in its chemistry, was used by Hippocrates, the founder of modern medicine, as a pain reliever more than 2,500 years ago. The use of boiled willow bark as a pain reliever and as a general aid to muscle and joint pain continued through the Middle Ages. Felix Hoffman (1868–1946), a scientist employed by the pharmaceutical company Bayer, modified the salicylic acid extracted from plant sources to produce aspirin, which became the largest selling pharmaceutical product in history. Aspirin has been a generic drug, not the subject of a corporate patent, since the 1930s, and it continues to be marketed by Bayer and numerous other pharmaceutical companies.

Aspirin was found to be effective as an anti-inflammatory, although the actual mechanism of how it acted on the COX enzymes was not determined until the 1970s. The second most famous of the NSAIDs is ibuprofen, approved for use in the United States by the Food and Drug Agency (FDA) in 1974; it is marketed under trade names such as Advil and Motrin. Both aspirin and ibuprofen are regarded as milder formulations of NSAIDs, with generally fewer side effects and a less pronounced anti-inflammatory action than more recently developed products. The current generation of NSAID medications are sometimes referenced as COX inhibitors.

It is a testament to the familiarity of these agents within the sports world that NSAIDs are consumed by all manner of athletes to help them manage minor pain. In the long-distance running world, aspirin and ibuprofen are commonly taken by recreational athletes before a marathon to anticipate the anti-inflammatory effects desired.

There are a number of physical advantages to the use of NSAIDs over other steroid-based anti-inflamma-tories, all of which must be assessed against their demonstrated risks to the user. These advantages include:

• There are fewer adverse reactions noted in NSAID use.
• Low-dose NSAIDs such as aspirin and ibuprofen have the additional demonstrated benefit of enhancing circulation; there is significant scientific data supporting aspirin and ibuprofen as inhibitors of excess blood clotting and reducing the risk of heart attack.
• NSAIDs are effective in the ongoing management of the pain associated with osteoarthritis.
• The use of NSAID, especially over the long term, presents risk of gastrointestinal tract bleeding, with risks of stomach, liver, and kidney disease.
• There are well-known interactions between NSAIDs of all types and other medications. As all NSAIDs have a blood-thinning capacity, the use of NSAIDs in conjunction with blood-thinning medication as used by some persons to lessen the risk of stroke may be dangerous.

SEE ALSO Glucocorticoids; Herbs; RICE (Rest/Ice/Compression/Elevation) treatment for injuries; Topical corticosteroids.