Drug | COX-1/COX-2 IC50 ratio*[1] | Half-life¶[2] |
Ibuprofen | 0.5 | 2 hours |
Naproxen | 0.7 | 12 to 17 hours |
6-MNA (active metabolite of nabumetone) | 1.5 | 24 hours |
Acetaminophen | 1.6 | 2 to 3 hours |
Indomethacin | 1.9 | 4.5 hours |
Meloxicam | 18 | 15 to 22 hours |
Diclofenac | 29 | 2 hours |
Celecoxib | 30 | 11 hours |
RofecoxibΔ | 267 | 17 hours[3] |
6-MNA: 6-methoxy-2-napthyl-acetic acid; COX: cyclooxygenase; IC50: half maximal inhibitory concentration; NSAIDs: nonsteroidal antiinflammatory drugs.
* The COX-1/COX-2 IC50 ratio (ie, IC50 of COX-1 divided by the IC50 of COX-2) may be used to characterize relative COX selectivity among NSAIDs. When the COX-1/COX-2 IC50 ratio is close to 1, the NSAID is considered nonselective. NSAIDs with COX-1/COX-2 IC50 ratios >1 are more potent inhibitors of COX-2 than COX-1, with COX-2 selectivity increasing with higher values. This table includes the COX-1/COX-2 IC50 ratio of selected NSAIDs as measured in vitro with human whole blood assays of COX-isoenzyme activity.[1] In vivo, COX-2 selectivity decreases with higher NSAID doses, particularly at doses above the usual dosing range.
¶ Half-life is based on data for oral formulations in adult patients with normal kidney function. Kidney impairment may result in prolonged elimination.
Δ Rofecoxib was withdrawn from the market due to an increased risk of myocardial infarctions and stroke associated with long-term use.With additional data from: