Concomitant use of coumarines and non-steroidal anti-inflammatory drugs (NSAIDs) may induce bleeding complications.
However, unlike non-selective NSAIDs, cyclo-oxygenase-2 (COX-2)-selective NSAIDs interfere very little with platelet aggregation.
In this study, researchers from the Netherlands assessed whether COX-2-selective NSAIDs are associated with less bleeding complications in coumarine users, when compared with non-selective NSAIDs.
The team performed a prospective, nested case-control study.
|NSAIDs were involved with 15% of bleeding events.|
|Quarterly Journal of Medicine|
They evaluated concomitant coumarine and NSAID users over a 2 year period.
Both cases and controls completed a questionnaire on bleeding risk factors.
The investigators recorded international normalized ratio (INR) values, and used both univariate and multivariate analyses were used to detect factors which contributed to bleeding.
The team found that there were 1491 bleeds, and NSAIDs were involved with 15%. However, 4% involved COX-2-selective NSAIDs.
The researchers found that for the non-bleeding controls there were 2601 prescriptions with a coumarine/NSAID combination. They found that 10% of these were COX-2-selective.
They calculated the adjusted ORs for a bleeding complication in patients using non-selective NSAIDs as 3.07, and in those using NSAIDs for more than 1 month as 3.01.
Dr Knijff-Dutmer's team concluded, "In coumarine users, COX-2-selective NSAIDs are associated with less bleeding complications than non-selective NSAIDs"
"Duration of NSAID use, as well as intensity of coumarine treatment, plays an important additional role".
"When the coumarine-NSAID combination is inevitable in an individual patient, a COX-2-selective NSAID may be preferred, with careful monitoring of the INR".