Cyclooxygenase-2 inhibitor

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Class of drugs that selectively inhibit cyclooxygenase-2 (COX-2)


Cyclooxygenase-2 inhibitors (COX-2 inhibitors) are a class of nonsteroidal anti-inflammatory drugs (NSAIDs) that selectively inhibit the enzyme cyclooxygenase-2 (COX-2). These drugs are used primarily for their anti-inflammatory, analgesic, and antipyretic properties while aiming to reduce gastrointestinal side effects associated with traditional NSAIDs.

Mechanism of Action[edit | edit source]

COX-2 inhibitors function by selectively blocking the cyclooxygenase-2 (COX-2) enzyme, which is responsible for:

  • The production of prostaglandins involved in pain and inflammation.
  • Mediating fever and swelling at injury sites.
  • Reducing pain perception by lowering prostaglandin levels in the nervous system.

Unlike traditional NSAIDs (e.g., ibuprofen and naproxen), COX-2 inhibitors spare cyclooxygenase-1 (COX-1), which plays a crucial role in:

  • Protecting the gastric lining.
  • Maintaining renal function.
  • Supporting platelet aggregation.

By selectively inhibiting COX-2, these drugs aim to reduce pain and inflammation while minimizing gastric ulceration and bleeding, a common side effect of non-selective NSAIDs.

Indications[edit | edit source]

COX-2 inhibitors are prescribed for:

Common COX-2 Inhibitors[edit | edit source]

List of Selective COX-2 Inhibitors
Drug Name Brand Names Status
Celecoxib Celebrex Widely used
Etoricoxib Arcoxia Approved in several countries, but not in the US
Parecoxib Dynastat Injectable COX-2 inhibitor
Rofecoxib Vioxx Withdrawn due to cardiovascular risks
Valdecoxib Bextra Withdrawn due to cardiovascular risks

Safety and Risks[edit | edit source]

Although COX-2 inhibitors offer gastrointestinal safety, they have been associated with increased risks of cardiovascular events such as:

  • Heart attack (myocardial infarction).
  • Stroke (ischemic stroke).
  • Hypertension (high blood pressure).

These risks led to the withdrawal of rofecoxib (Vioxx) and valdecoxib (Bextra) from the market. The FDA and EMA continue to monitor the safety of celecoxib and other COX-2 inhibitors.

Comparison with Traditional NSAIDs[edit | edit source]

Comparison of COX-2 Inhibitors vs. Traditional NSAIDs
Feature COX-2 Inhibitors Traditional NSAIDs
Gastrointestinal Safety Lower risk of ulcers and bleeding Higher risk of ulcers and GI bleeding
Cardiovascular Risk Increased risk Variable risk
Platelet Effects No significant inhibition of platelets Inhibits platelet aggregation
Anti-inflammatory Action Similar to NSAIDs Strong anti-inflammatory effect

Contraindications[edit | edit source]

COX-2 inhibitors should be avoided in:

  • Patients with a history of heart disease or stroke.
  • Individuals with severe kidney disease.
  • Those allergic to sulfonamides (some COX-2 inhibitors contain sulfa components).
  • Pregnant women, particularly in the third trimester.

Drug Interactions[edit | edit source]

COX-2 inhibitors may interact with:

  • Aspirin – May negate the gastrointestinal safety benefits.
  • Warfarin and other anticoagulants – Increased risk of bleeding.
  • Diuretics (e.g., furosemide, hydrochlorothiazide) – May reduce diuretic effectiveness.
  • ACE inhibitors and ARBs – Can impair kidney function when used together.

Current Regulatory Status[edit | edit source]

  • Rofecoxib (Vioxx) – Withdrawn worldwide in 2004 due to cardiovascular risks.
  • Valdecoxib (Bextra) – Withdrawn in 2005.
  • Celecoxib (Celebrex) – Still available but with cardiovascular risk warnings.
  • Etoricoxib (Arcoxia) – Approved in Europe, Asia, and Latin America, but not in the United States.

Research and Future Developments[edit | edit source]

New research is focused on:

  • Developing safer COX-2 inhibitors with reduced cardiovascular risks.
  • Studying COX-2 inhibition in cancer therapy.
  • Investigating the role of COX-2 inhibitors in Alzheimer’s disease and neurological conditions.

See Also[edit | edit source]

References[edit | edit source]

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