Assessment of Common Nonsteroidal Anti-Inflammatory Medications by Whole Blood Aggregometry: A Clinical Evaluation for the Perioperative Setting

ObjectiveTo help define the perioperative risk related to commonly used non-aspirin NSAIDs with whole blood platelet aggregometry.MethodsTwelve healthy volunteers were recruited. Two cyclooxygenase (COX)-1 inhibitors (ibuprofen and naproxen) and two COX-2 inhibitors (meloxicam and celecoxib) were administered, and daily whole blood platelet aggregometry studies were obtained until studies showed no platelet inhibition. Aspirin was studied at the conclusion of the study.ResultsIbuprofen had no inhibitory effect on platelet aggregation in all women and no inhibitory effect in 83% of men at 24 hours. All platelet function had returned to normal at 48 hours. The inhibitory effect of naproxen on platelets was absent at 48 hours in 83% of the women and 50% of men. By 72 hours all platelet studies had returned to normal. Meloxicam and celecoxib did not cause any overall inhibitory effect on platelet aggregation.ConclusionsIbuprofen and naproxen have a mild inhibitory effect on platelet aggregation compared with aspirin and this effect is undetectable by 48 hours and 72 hours, respectively. Meloxicam and celecoxib show essentially no inhibitory effect on platelet aggregation. These findings suggest that there is little bleeding risk related to platelet aggregation at 24 hours in patients who take COX-2 inhibitors and at 72 hours for those who take COX-1 inhibitor medications.