Nonsteroidal Anti-inflammatory Drug

Nonsteroidal Anti-inflammatory Drug (NSAID), any of a large group of drugs that reduce pain and inflammation in muscles and joints. NSAIDs work by blocking the production of prostaglandins, body chemicals that cause inflammation and contribute to the brain’s perception of pain. NSAIDs are among the most commonly used drugs in the world. In the United States alone, 33 million people regularly take these drugs, spending $4 billion annually.

NSAIDs are available over the counter and by prescription, and include aspirin, ibuprofen, naproxen, indomethacin, oxaprozin, nabumetone, and many other similar drugs. A remarkably versatile group of drugs, NSAIDs relieve a variety of minor, everyday aches and pains as well as play an important role in the treatment of a number of chronic diseases, particularly arthritis. As such, they may be incorporated into long-term treatment programs that require the careful supervision of a qualified physician.

More recently scientists have been investigating possible new uses for NSAIDs in preventing various diseases. For example, low doses of aspirin prevent blood from clotting and can help ward off heart attacks and strokes, which are among the leading causes of death in the United States. The American Heart Association now recommends that people with a personal or family history of heart attack may benefit from taking one aspirin every other day as a preventive measure. Preliminary studies show that certain NSAIDs, especially sulindac, a drug used to treat arthritis, may prevent some forms of colorectal cancer. Other emerging data suggest that different NSAIDs, particularly ibuprofen, may have a role in preventing Alzheimer’s disease.

For all of their benefits, however, NSAIDs are not without risks, some of them severe. The most common side effects from NSAID use affect the digestive system. In addition to their role in pain perception and inflammation, prostaglandins help protect the lining of the digestive tract from corrosive stomach acid. When NSAIDs inhibit prostaglandin production, the digestive tract is left unprotected, resulting in problems ranging from minor discomfort, such as upset stomach, to life-threatening ulcers and bleeding from the stomach or intestine. NSAIDs can also cause problems with the kidneys, liver, brain, skin, and other organs. Although only a small percentage of NSAID users develop serious side effects, NSAID side effects pose a major health problem because the drugs are used by so many people. In the United States, NSAIDs are responsible for over 100,000 hospitalizations and over 10,000 deaths each year, mostly due to bleeding from the stomach or intestine.

The risk of side effects is greatest in older people, in the disabled, in patients who are also taking the anti-inflammatory steroid prednisone, and in those who take high doses of NSAIDs for long periods of time to control arthritis or other chronic diseases. For those who must use NSAIDs for extended periods, doctors may prescribe a synthetic prostaglandin called misoprostol to help protect the stomach lining.

Scientists are working to develop safer NSAIDs by targeting inflammation more precisely. NSAIDs block prostaglandin production by inhibiting an enzyme known as cyclooxygenase, or COX. The enzyme has two forms, known as COX-1 and COX-2. COX-1 is involved in producing the prostaglandins that protect the stomach lining, while COX-2 is involved in inflammation. The next generation of NSAIDs will selectively target COX-2 while allowing the activity of COX-1 to continue. Preliminary evidence suggests that these drugs will prove to be safer than most current NSAIDs.

Like all drugs, NSAIDs can interact with other medications. The drugs inhibit blood clotting, which can be dangerous in patients who are also taking other anticoagulant drugs. NSAIDS can also cause fluid retention in patients who are taking certain medications for congestive heart failure.