Description

Celecoxib is a synthetic nonsteroidal anti-inflammatory drug (NSAID) that belongs to a class of drugs known as selective cyclooxygenase-2 (COX-2) inhibitors. Unlike traditional NSAIDs, which inhibit both COX-1 and COX-2 enzymes, celecoxib’s unique chemical structure allows it to target the COX-2 enzyme with a high degree of specificity. This selectivity is the basis for its therapeutic effects and its more favorable gastrointestinal safety profile. It is available in oral capsules.

Indications

Celecoxib is primarily indicated for the treatment of inflammatory and painful conditions, particularly those requiring chronic management. Its key indications include:

• Osteoarthritis (OA): For the symptomatic relief of pain and inflammation associated with OA.

• Rheumatoid Arthritis (RA): For the symptomatic relief of RA, including the relief of signs and symptoms of juvenile rheumatoid arthritis in patients 2 years and older.

• Ankylosing Spondylitis: For the symptomatic relief of pain and inflammation in this chronic inflammatory disease of the spine.

• Acute Pain: For the management of acute pain, such as that following dental surgery or other minor surgical procedures.

• Primary Dysmenorrhea: For the relief of menstrual cramps and pain.

Mechanism of Action

The mechanism of action of celecoxib is based on its ability to selectively inhibit the enzyme cyclooxygenase-2 (COX-2), thereby reducing the production of inflammatory prostaglandins.

1. Selective Inhibition of COX-2: Celecoxib works by specifically and potently inhibiting the activity of the cyclooxygenase-2 (COX-2) enzyme.

2. Role of COX-1 vs. COX-2:
   • COX-1 is a constitutively expressed enzyme that is involved in normal physiological functions, such as maintaining the protective gastric mucosal lining, promoting platelet aggregation, and regulating renal blood flow.

• • COX-2 is an inducible enzyme that is primarily expressed at the site of inflammation in response to cytokines and other inflammatory mediators. It is responsible for the production of prostaglandins that cause pain, swelling, and fever.

3. Blocking Prostaglandin Synthesis: By selectively inhibiting COX-2, celecoxib blocks the production of the prostaglandins that mediate the symptoms of inflammation, pain, and fever.

4. Minimizing Gastrointestinal Side Effects: Because celecoxib largely spares the COX-1 enzyme, it does not interfere with the production of the protective prostaglandins in the stomach. This selectivity is what provides its primary clinical advantage: a significantly lower risk of gastrointestinal side effects (e.g., ulcers, bleeding) compared to non-selective NSAIDs like ibuprofen or naproxen, which inhibit both COX-1 and COX-2.

In summary, celecoxib is a selective COX-2 inhibitor that provides effective relief from pain and inflammation by targeting the enzymes responsible for these symptoms while largely sparing the enzyme that protects the gastrointestinal tract.