COX-2 inhibitors, because of their selectivity, are less likely than NSAIDs to produce any adverse GI or renal effects. Only celecoxib is currently available for use in the United States; rofecoxib and valdecoxib were removed from the market because of adverse effects. Celecoxib (100 mg twice daily) has been useful in reducing pain associated with osteoarthritis; a dosage of200 mg twice daily has been employed to manage rheumatoid arthritis and sickle cell pain.
Concerns have been raised regarding the cardiovascular safety of the COX-2 inhibitors. The alleged mechanism underlying the risk for adverse cardiovascular events is thought to be related to the prothrombotic effects of the COX-2
inhibitors. Specifically, by interfering with the COX-2 enzyme, these agents interfere with prostacyclin formation, which confers beneficial vascular effects. Because these agents do not block the COX-1 enzyme, the formation of thromboxane A2 goes unchecked (see Figure 5-1). The latter confers prothrom-botic effects, predisposing patients to potential risks of myocardial infarction, ischemic stroke, pulmonary embolism, and so on.
As a result, use of COX-2 inhibitors should be avoided in patients with risk factors for cardiovascular events (e.g., hypertension, hyperlipidemia, diabetes mellitus, cigarette smoking). Use is contraindicated in patients with congestive heart failure, ischemic heart disease, cerebrovascular disease, or severe peripheral arterial disease, as well as patients with sensitivities to COX-2 inhibitors or allergies to sulfonamides or NSAIDs. Concomitant use of aspirin, although it reduces risk of cardiovascular complications, may increase GI complications that would otherwise have been preventable with use of the COX-2 inhibitor.
Was this article helpful?
Thank you for deciding to learn more about the disorder, Osteoarthritis. Inside these pages, you will learn what it is, who is most at risk for developing it, what causes it, and some treatment plans to help those that do have it feel better. While there is no definitive “cure” for Osteoarthritis, there are ways in which individuals can improve their quality of life and change the discomfort level to one that can be tolerated on a daily basis.