COX-2 Inhibitors
Wellness & SelfcareDrugs

COX-2 Inhibitors

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Updated on October 30, 2024
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COX-2 inhibitors, also known as selective COX-2 inhibitors, are nonsteroidal anti-inflammatory drugs (NSAIDs) that treat inflammatory pain. They’re available by prescription and may be easier on your stomach than other NSAIDs. COX-2 inhibitors do have potential side effects, including some that may affect the heart and cardiovascular system. Read on to learn more.

What Are COX-2 Inhibitors?

COX-2 inhibitors are a type of NSAID (nonsteroidal anti-inflammatory drug) that treat inflammation and pain. They’re called COX-2 inhibitors because they inhibit, or block, an enzyme (COX-2) that’s responsible for inflammation and other responses of the immune system.

COX-2 inhibitors are available with a prescription. They’re most suitable for mild-to-moderate pain. They may be a better choice of NSAID if you have a history of gastrointestinal bleeding because the enzyme they block isn’t involved in protecting the stomach lining. However, they’re not without side effects.

What Conditions Do COX-2 Inhibitors Treat?

COX-2 inhibitors help treat pain in some inflammatory conditions by calming down the immune system’s response. When the immune system is attacked by a virus, bacterium, or a foreign object (like in the case of injury), it responds with an inflammatory process such as fever, pain, or swelling at the injury site. This is a natural response that helps the healing process. But too much inflammation, or inflammation that’s the result of the immune system attacking its own tissue (like in the case of autoimmune conditions) — can be a sign of illness.

COX-2 Inhibitors Condition List

COX-2 inhibitors treat several conditions, including:

Types of COX-2 Inhibitors

Celecoxib (Celebrex) is currently the only COX-2 inhibitor available in the United States.

Other COX-2 inhibitors have been taken off the U.S. market or are not approved in the U.S. due to safety concerns:

  • Rofecoxib (Vioxx) was recalled worldwide due to concerns about adverse cardiovascular effects, like heart attacks and strokes.
  • Valdecoxib (Bextra) was withdrawn from U.S. and European Union markets due to cardiovascular risks and life-threatening skin reactions.
  • Prexige (Lumiracoxib) was withdrawn from much of the world market because of concerns about severe liver damage. It’s not approved in the United States.
  • Etoricoxib (Arcoxia) is available in other countries, but it’s not approved in the United States.
  • Parecoxib (Dynastat) is available in other countries but not in the United States.

How Do COX-2 Inhibitors Work?

COX-2 inhibitors work by blocking the COX-2 enzyme. There are two types of COX (short for cyclooxygenase) enzymes: COX-1 and COX-2. Both help create prostaglandins, which are hormone-like chemicals in the body that regulate pain and inflammation.

The main role of COX-1 enzymes is actually to create prostaglandins that activate platelets (tiny blood cells that help create blood clots and stop bleeding) and protect the stomach and gastrointestinal lining. On the other hand, COX-2 enzymes produce prostaglandins after infection or injury.

By selectively blocking only COX-2 enzymes but not COX-1, COX-2 inhibitors ease inflammation and pain with fewer adverse effects on your gastrointestinal tract than other NSAIDs.

What Are the Possible Side Effects of COX-2 Inhibitors?

Although COX-2 inhibitors may be easier on your tummy than other NSAIDs, they’re not completely without side effects. These side effects are more likely if you take the drugs at a higher dose than recommended, or for longer than you should.

Some of the gastrointestinal side effects COX-2 inhibitors may cause include:

  • Diarrhea
  • Constipation
  • Bloating
  • Nausea
  • Upset stomach
  • Vomiting
COX-2 inhibitors may also:

  • Affect how well your kidneys function
  • Cause water retention, resulting in swelling in the arms and legs (edema)
  • Raise potassium levels
  • Raise your risk of heart attack and stroke

Other potential cardiovascular side effects include:

  • High blood pressure
  • Congestive heart failure
  • Heart palpitations

Are There Any Risks Related to COX-2 Inhibitors?

COX-2 inhibitors are generally safe, however there are a few conditions when you shouldn’t take them. For example, you shouldn’t take selective COX-2 inhibitors if you have any of the following medical conditions:

  • Chronic renal insufficiency or liver failure
  • An asthma attack or other severe allergic reaction from taking aspirin, another NSAIDs like ibuprofen, or sulfonamide antibiotics (also called “sulfa” drugs)

You should also avoid all NSAID drugs (including COX-2 inhibitors) if you:

  • Plan to have surgery soon, which may increase your risk of bleeding
  • Have a history of recent heart surgery, especially a coronary artery bypass graft (CABG)
Consult your healthcare professional before taking COX-2 inhibitors if you:

The Takeaway

  • Selective COX-2 inhibitors are a type of NSAID used for treating pain and inflammation.
  • Other NSAIDs can lead to stomach and intestinal problems for some people, but COX-2 inhibitors have a lower risk of gastrointestinal upset.
  • If you’re at risk for, or already have, gastrointestinal problems, selective COX-2 inhibitors may be a better option for you. However, COX-2 inhibitors are not without side effects. Consult your doctor about the risks of these prescription drugs.
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Kristina D. Carter, PharmD, is a clinical pharmacist and freelance health writer who currently works in a managed care setting, performing quality audits on utilization management case reviews for the pharmacy team. She has over 20 years of experience and has worked in several pharmacy practice settings, including at a community pharmacy as well as in ambulatory care, senior care, and pharmacy operations.

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Resources
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