Using COX-2 inhibitors—Celebrex 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. For more information, click to the Bextra homepage. For more information on safe use of COX-2 inhibitors and other NSAIDs, please see Understanding COX-2 inhibitor side effects. Discovery of COX-2 inhibitors - a new type of NSAID The cyclooxygenase (COX) enzyme was first isolated in 1976. However, in 1991 it was discovered that there are actually two enzymes: COX-1 and COX-2. The COX-2 enzyme is the majority of the enzyme at the site of inflammation, and has very little activity in the stomach, kidneys or platelets. Therefore, inhibiting the COX-2 enzyme not only helps limit inflammation, but also has fewer side effects than traditional (non-selective) NSAID's because it does not affect the COX-1 mediated functions of the body (i.e. maintaining the stomach lining). Choosing a COX-2 inhibitor There are four questions that should be considered when looking at a COX-2 inhibitor NSAID: Is the COX-2 inhibitor agent selective? (An agent must be more than 100-fold more COX-2 selective than COX-1 to meet this criteria.) Does the COX-2 inhibitor agent have a sparing effect for stomach ulcers? Does the COX-2 inhibitor agent spare platelet function? Is the COX-2 inhibitor agent effective clinically? Celebrex—new COX-2 inhibitor There is a new drug that is very selective in its inhibition of COX-2: Celecoxib (e.g. Celebrex). COX-2 inhibitors have been found to be equally as effective as more traditional NSAIDs (e.g. naprosyn, diclofenac, or ibuprofen), yet far less likely to disrupt the stomach lining. Their ulceration rate has been found to be equivalent to placebo in clinical trials. Only 2 out of 5,285 patients had a significant gastrointestinal complication while taking Celebrex. Safe use of Celebrex The recommended dosage for Celebrex is 100-200 mg twice a day. Celebrex was found to have steady state levels within 5 days of continued usage, and have peak levels in the blood stream 3 hours after a dose. Unlike older NSAID's, COX-2 inhibitors like Celebrex do not need to be taken with food. In fact, COX-2 inhibitors should not be taken in conjunction with antacids or a fatty meal, as this limits their absorption. Patients who are on blood thinners (e.g. Coumadin) may take these drugs because they do not interfere with platelet function. Editorial Note: In addition, new potential risks and side effects of COX-2 inhibitors and other NSAIDs have been studied. For more information, please see Understanding COX-2 inhibitor side effects.