Because COX-2 inhibitors such as Celebrex and Bextra do not impair blood clotting, they are recommended for patients taking medications such as warfarin (Coumadin) to thin the blood. This type of pain reliever can be taken after surgery without the risk of increased bleeding. COX-2 inhibitors also are less likely to cause gastrointestinal side effects and ulcers, according to Spine-Health.
COX-2 inhibitor nonsteroidal anti-inflammatory drugs, or NSAIDs, block the receptor site of the enzyme COX-2 without blocking COX-1, an enzyme that protects the stomach lining. This reduces the risk of gastrointestinal disorders. However, the COX-2 inhibitor Vioxx was recalled after studies showed an elevated risk of heart disease for patients taking it for longer than 18 months. Studies involving Celebrex and Bextra showed mixed results, with one study showing patients who took 400 milligrams of Celebrex had 2.5 times greater incidence of fatal and nonfatal heart attacks and strokes, and 3.4 times greater incidence for patients taking 800 milligrams. A subsequent study showed no increased risk with 400 milligrams daily. Use of COX-2 inhibitors by the elderly and for long periods of time has been linked to gastrointestinal problems, liver problems and kidney disease. The FDA warns consumers to take only the recommended dosage of NSAIDs and for no longer than 10 days.