Name: China Manufacturer Supply High Quality Parecoxib Sodium Valdecoxib CAS 181695-72-7
Brand: Wuhan Fortuna Chemical Co., Ltd.

Specifications of Valdecoxib CAS 181695-72-7

Items	Specification
Product name	Valdecoxib
CAS	181695-72-7
Appearance	White to off-white powder
Assay	≥99%
Molecular Formula	C16H14N2O3S
Molecular Weight	314.36
EINECS	803-082-3

Parameters of Valdecoxib CAS 181695-72-7

Product parameters
Cas number:	181695-72-7
Appearance:	White to off-white powder
Purity:	99%min
Package details:	100g,1kg/foil bag
Brand:	Fortunachem

Valdecoxib is a prescription-only nonsteroidal anti-inflammatory drug (NSAID) that belongs to the COX-2 inhibitor class (coxibs). It was marketed under the brand name Bextra® by Pfizer. It was approved for treating pain and inflammation from osteoarthritis, rheumatoid arthritis, and menstrual cramps (dysmenorrhea). However, due to serious safety concerns, it was voluntarily withdrawn from the global market in 2005.

1. Chemical and Pharmacological Definition

Chemical Class: Sulfonamide-containing diaryl-substituted pyrazole. It is a selective COX-2 inhibitor.
Mechanism of Action: It works by selectively blocking the cyclooxygenase-2 (COX-2) enzyme. This enzyme is responsible for producing prostaglandins, which are chemicals that promote inflammation, pain, and fever. By inhibiting COX-2 more than COX-1, it was designed to provide anti-inflammatory benefits with a lower risk of stomach ulcers and bleeding compared to traditional NSAIDs like ibuprofen or naproxen.

2. Key Properties and Original Uses

Therapeutic Use: It was effective for:
Osteoarthritis
Rheumatoid Arthritis
Primary Dysmenorrhea (painful menstrual periods)
Administration: Oral tablets.
Benefit (Theoretical): Its high selectivity for COX-2 meant it offered potent anti-inflammatory and analgesic effects while minimizing the gastrointestinal toxicity (e.g., ulcers) associated with non-selective NSAIDs that also block the protective COX-1 enzyme.

3. The Reason for Withdrawal (Safety Concerns)

Valdecoxib's withdrawal was not due to a lack of efficacy but because of an unacceptable risk of severe, life-threatening adverse events:

Serious Skin Reactions: Including fatal cases of Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN), which cause severe skin peeling and blistering.

Cardiovascular Risks: Like other COX-2 inhibitors (e.g., rofecoxib/Vioxx®), it was associated with an increased risk of heart attack (myocardial infarction), stroke, and blood clots.

Other Risks: It also carried warnings about rare but serious allergic reactions.

The U.S. Food and Drug Administration (FDA) requested its withdrawal after determining that the drug's overall risks outweighed its benefits. Pfizer complied, removing Bextra from the market in April 2005.

4. Comparison with Other NSAIDs

Drug Name	Brand Name (Example)	COX Selectivity	Market Status	Key Risk
Valdecoxib	Bextra	Selective COX-2 Inhibitor	Withdrawn (2005)	Serious skin reactions, CV events
Rofecoxib	Vioxx	Selective COX-2 Inhibitor	Withdrawn (2004)	Cardiovascular events
Celecoxib	Celebrex	Selective COX-2 Inhibitor	Still on the market	CV events (has boxed warning)
Ibuprofen	Advil, Motrin	Non-selective (COX-1 & COX-2)	On the market	GI bleeding, kidney issues
Naproxen	Aleve, Naprosyn	Non-selective (COX-1 & COX-2)	On the market	GI bleeding (lower CV risk than coxibs)

Conclusion

Valdecoxib is a former COX-2 inhibitor painkiller that was effective but removed from sale worldwide due to its link to rare but extremely serious skin reactions and an increased risk of heart attack and stroke. Its history is a significant case study in pharmacovigilance (drug safety monitoring), demonstrating the importance of post-market surveillance to detect rare adverse events that may not be apparent in pre-approval clinical trials.