NSAIDs may be grouped according to their preference for COX-1 and COX-2 enzymes. Those that favor COX-1 are more likely to cause gastrointestinal side effects. Those that favor COX-2 have a higher risk of cardiovascular effects but less gastrointestinal effects. Higher dosages of NSAIDs tend to result in more COX-2 enzyme inhibition (and more cardiovascular side effects), even in those NSAIDs traditionally seen as low risk (such as ibuprofen). NSAIDs with higher activity against COX-2 enzymes should be used with caution in people with cardiovascular disease or at increased risk of cardiovascular disease.
In the past several years, some newer medications have come on the market; these are commonly referred to as COX-2 inhibitors . Remember, all NSAIDs work against cyclooxygenase (COX). Traditional NSAIDs (. Ibuprofen, Motrin, Aleve) work against both COX-1 and COX-2. COX-1 and COX-2 are both types of cyclooxygenase enzymes that function in your body. The new medications (. Celebrex) work primarily against COX-2, and allow COX-1 to function normally. Because COX-1 is more important in producing the protective lining in your gut (gastric mucosa), these newer NSAIDs are believed to have less of a risk of causing stomach ulcers.