Vioxx

Rofecoxib

Clinical data
Pregnancy category	AU: C
Routes of administration	oral
ATC code	M01AH02 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) withdrawn
Pharmacokinetic data
Bioavailability	93%
Protein binding	87%
Metabolism	hepatic
Biological half-life	17 hours
Excretion	biliary/renal
Identifiers
IUPAC name 4-(4-methylsulfonylphenyl)-3-phenyl-5H-furan-2-one
CAS Number	162011-90-7 Y
PubChem CID	5090
IUPHAR/BPS	2893
DrugBank	DB00533 Y
ChemSpider	4911 Y
UNII	0QTW8Z7MCR
KEGG	D00568 Y
ChEBI	CHEBI:8887 Y
ChEMBL	CHEMBL122 Y
ECHA InfoCard	100.230.077
Chemical and physical data
Formula	C17H14O4S
Molar mass	314.357 g/mol
3D model (Jmol)	Interactive image
SMILES O=C2OCC(=C2\c1ccccc1)\c3ccc(cc3)S(=O)(=O)C
InChI InChI=1S/C17H14O4S/c1-22(19,20)14-9-7-12(8-10-14)15-11-21-17(18)16(15)13-5-3-2-4-6-13/h2-10H,11H2,1H3 Y Key:RZJQGNCSTQAWON-UHFFFAOYSA-N Y

Rofecoxib /ˌrɒfᵻˈkɒksɪb/ is a nonsteroidal anti-inflammatory drug (NSAID) that has now been withdrawn over safety concerns. It was marketed by Merck & Co. to treat osteoarthritis, acute pain conditions, and dysmenorrhea. Rofecoxib was approved by the U.S. Food and Drug Administration (FDA) on May 20, 1999, and was marketed under the brand names Vioxx, Ceoxx, and Ceeoxx.

Rofecoxib gained widespread acceptance among physicians treating patients with arthritis and other conditions causing chronic or acute pain. Worldwide, over 80 million people were prescribed rofecoxib at some time.

On September 30, 2004, Merck withdrew rofecoxib from the market because of concerns about increased risk of heart attack and stroke associated with long-term, high-dosage use. Merck withdrew the drug after disclosures that it withheld information about rofecoxib's risks from doctors and patients for over five years, resulting in between 88,000 and 140,000 cases of serious heart disease. Rofecoxib was one of the most widely used drugs ever to be withdrawn from the market. In the year before withdrawal, Merck had sales revenue of US$2.5 billion from Vioxx. Merck reserved $970 million to pay for its Vioxx-related legal expenses through 2007, and has set aside $4.85bn for legal claims from US citizens.

Rofecoxib was available on prescription in both tablet-form and as an oral suspension. It was available by injection for hospital use.

Cyclooxygenase (COX) has two well-studied isoforms, called COX-1 and COX-2. COX-1 mediates the synthesis of prostaglandins responsible for protection of the stomach lining, while COX-2 mediates the synthesis of prostaglandins responsible for pain and inflammation. By creating "selective" NSAIDs that inhibit COX-2, but not COX-1, the same pain relief as traditional NSAIDs is offered, but with greatly reduced risk of fatal or debilitating peptic ulcers. Rofecoxib is a selective COX-2 inhibitor, or "coxib".