Which of the following medications increases the risk of bleeding in patients taking Coumadin?

Non-steroidal anti-inflammatory drugs (NSAIDs) increase the risk of bleeding in patients taking Coumadin due to their effects on platelet function and the gastrointestinal tract. NSAIDs inhibit the enzyme cyclooxygenase (COX), which leads to decreased production of thromboxane A2, a substance that promotes platelet aggregation. This inhibition can result in prolonged bleeding time when taken with anticoagulants like Coumadin, which already increases the risk of bleeding by its mechanism of action that prevents blood clot formation.

Additionally, NSAIDs can irritate the gastric mucosa, potentially leading to gastrointestinal bleeding—this risk is exacerbated in patients who are also on anticoagulant therapy. Thus, combining NSAIDs with Coumadin significantly heightens the potential for bleeding complications, making it vital for healthcare providers to monitor patients for any signs of bleeding when these medications are co-administered.