Department of Pharmacy, Virginia Commonwealth University, Medical College of Virginia, Richmond, Virginia.
Clinical Implications of Drug Interactions with Coxibs
Article first published online: 17 JAN 2012
2001 Pharmacotherapy Publications Inc.
Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy
Volume 21, Issue 10, pages 1223–1232, October 2001
How to Cite
Garnett, W. R. (2001), Clinical Implications of Drug Interactions with Coxibs. Pharmacotherapy, 21: 1223–1232. doi: 10.1592/phco.21.15.1223.33891
- Issue published online: 17 JAN 2012
- Article first published online: 17 JAN 2012
Nonsteroidal antiinflammatory drugs (NSAIDs) often are prescribed to patients who are taking concomitant drugs. Cyclooxygenase (COX)-2 inhibitors (coxibs) rofecoxib and celecoxib are highly selective inhibitors of COX-2, differentiating them from nonselective NSAIDs, which substantially inhibit both COX-1 and COX-2. Like nonselective NSAIDs, coxibs are hepatically metabolized: rofecoxib primarily by reduction by cytosolic enzymes and celecoxib by the cytochrome P450 (CYP) enzyme system. Because rofecoxib is not significantly metabolized by CYP, it has fewer confirmed or potential drug interactions than celecoxib. However, potent inducers of CYP, such as rifampin, may decrease rofecoxib concentrations because of induction of general hepatic metabolic activity. Celecoxib is metabolized by CYP2C9 and may be increased or decreased by CYP2C9 modifiers. It also inhibits CYP2D6 and may affect concentrations of CYP2D6 substrates. Similar to NSAIDs, many pharmacodynamic interactions involving coxibs are related to inhibition of production of renal prostaglandins. However, coxibs have no antiplatelet activity and may be preferred to NSAIDs in patients receiving antithrombotic therapy. Nonetheless, when a potential for an interaction exists, standard monitoring is recommended when starting or discontinuing a coxib. Due to lack of data to support these interactions, which are primarily theoretical, additional studies are necessary to establish the drug interaction profiles of coxibs.