On April 7, 2005 the Food and Drug Administration requested that Pfizer suspend sales of Bextra in the United States. As a result, Bextra will no longer be available to patients in the United States.
Since the September 2004 recall of Vioxx, recent studies have raised questions about the potential side effects of COX-2 inhibitors.
Overview of Celebrex and Bextra
Two pain medications – Celebrex (chemical name: celecoxib) and Bextra (chemical name: valdecoxib) – are the some of the first drugs approved by the U.S. Food and Drug Administration (FDA) that are classified as selective COX-2 inhibitors, a relatively new class of non-steroidal anti-inflammatory drugs (NSAIDs). COX-2 inhibitors work by limiting the formation of inflammation, which is a common component of many forms of back pain and neck pain. Celebrex and Bextra are commonly prescribed for arthritis pain (i.e. osteoarthritis) and different types of back pain.
The main difference between COX-2 inhibitors such as Celebrex and Bextra versus traditional anti-inflammatory drugs (such as aspirin, ibuprofen, or naproxen) is that COX-2 inhibitors only selectively inhibit the COX-2 enzyme (cyclooxygenase-2).
In 1991, research discovered that the COX enzyme actually had two isoforms: COX-1 and COX-2. The differences between the two isoforms are as follows:
- The COX-1 enzyme works to maintain the integrity of the lining of the stomach. It also helps maintain normal platelet and kidney functions.
- The COX-2 enzyme is associated with instances of inflammation, as well as fever and pain.
Thus, suppression of only the COX-2 enzyme with a medication like Bextra or Celebrex helps treat the symptoms from inflammation without stifling the important functions of the COX-1 enzyme.
In the past, patients who took traditional NSAIDs had the risk of multiple side effects, including: gastrointestinal tract symptoms such as stomach ulcers and heartburn, excess bleeding from loss of platelet function, and degradation of renal blood flow in the kidneys. With selective COX-2 inhibitors, patients can take a medication that allows the COX-1 enzyme to maintain its necessary functions.
New Information about COX-2 Inhibitors and Potential Health Risks
Another major brand of COX-2 inhibitor, Vioxx, was voluntarily withdrawn from the market in September 2004 by Merck, the drug’s manufacturer. The recall was due to new information from clinical trials showing that certain patients taking the drug for longer than 18 months were at risk for developing serious cardiovascular problems (such as heart attack or stroke).
Recent studies (although still inconclusive) have raised questions about the potential health risks of COX-2 inhibitors Celebrex and Bextra, as well as other drugs that are classified as NSAIDs.
Guidelines for Using Celebrex and Bextra
The current major brands of COX-2 inhibitors (Celebrex and Bextra) have been developed with the goal of reducing pain and inflammation with as few side effects as possible. Although the overall medications are quite similar, each of the brands is based on a different chemical composition that produces some differences in dosages, possible side effects, etc.