Nonsteroidal Anti-inflammatory Drugs

What are nonsteroidal anti-inflammatory drugs (NSAIDS)?

NSAIDS are medications, which are designed to decrease inflammation, pain, and stiffness in the joints and muscles. They are called “nonsteroidal” to differentiate them from the corticosteroid class of drugs (for example, prednisone), which is also used to treat arthritis and other musculoskeletal conditions.

How do NSAIDS work?

NSAIDS work mainly by blocking the production of molecules called prostaglandins. These molecules are the end-product of the breakdown of a substance called arachidonic acid which is an integral part of most cells. An enzyme called cyclooxygenase breaks down the rachidonic acid. There are two major forms of cyclooxygenase: cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). When COX-1 is activated, prostaglandins which are helpful and protective to the body are made. When COX-2 is activated, prostaglandins which cause pain, fever, and inflammation are made. The older, traditional NSAIDS, such as ibuprofen, naproxen, work by blocking both COX-1 and COX-2. The newer drugs on the market, such as celecoxib and rofecoxib, work by blocking COX-2 and sparing COX-1. This COX selectivity allows the newer NSAIDS to block the “bad” prostaglandins while saving the “protective” prostaglandins.

What are the side effects of the NSAIDS?

The NSAIDS require careful prescribing by a physician and very close monitoring by a physician. The major side effect of both the COX-l and COX-2 is on the gastrointestinal (GI) system, although the COX-2 drugs have a significantly lower incidence of adverse GI events. The FDA required the pharmaceutical companies developing the COX-2 drugs to perform extensive trials to prove that their drugs were safer on the GI system. These trials have indeed shown that the COX-2 drugs are safer. The traditional NSAIDS had a higher incidence of gastritis, ulcers, perforations, and even GI bleeding than the newer COX-2 drugs. Taking aspirin or aspirin containing compounds (for example, excedrin) or taking over-the-counter NSAIDS (for example, advil) while taking a prescribed NSAID increases the risk of GI events. There are other risk factors, which would increase the likelihood of a GI event or bleed while taking NSAIDS. These would include, for example, older age, serious systemic illnesses, previous ulcer history, or the use of multiple other medications. Of course, if a person is on an anticoagulant, the NSAIDS should not be used.

The prostaglandins are also found in the kidney, so that blocking them at the kidney level can cause kidney side effects. This holds for both the COX-1 and the COX-2 drugs. This can result in salt and water accumulation and swelling. Sometimes, the function of the kidney decreases, so that other medications a patient is taking are not metabolized correctly. Older persons who have heart disease are at risk to develop heart failure. NSAIDS can also cause an allergic reaction in the kidney , which usually reverses when the drug is withdrawn.

NSAIDS in general can affect the bone marrow’s production of cells. This can results in anemia, low white blood cell count, or low platelet count. Sometimes the liver reacts to the NSAIDS and a type of liver inflammation occurs. Rarely, severe liver disease can result.

Rarely, the NSAIDS can cause effects in the central nervous system, so that headaches or confusion or even meningitis happens. The NSAIDS can also affect the skin and cause minor or severe rashes.

Who should take NSAIDS?

Even though NSAIDS are available in over-the-counter products, these medications are serious formulations and should not be taken without a physician’s advice or prescription. Because of the side effects of these drugs and because of potential drug interactions, one should always inform their physician if they are using the over-the-counter preparations. These drugs are helpful in treating musculoskeletal conditions including arthritis, as well as other pain syndromes. Before NSAIDS are prescribed or taken, however, a thorough history and physical examination should be performed by a qualified physician to help establish a diagnosis. Then the medication needs to be monitored according to the individual patient’s needs. The physician will then exercise her judgment as to whether or not the individual would benefit from and not be harmed by the use of an NSAID.

Authored by: Carolyn Smith, M.D.

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