Effect of nabumetone and aspirin on colonic mucosal bleeding time

The management of patients taking aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) who require colonoscopy remains controversial because of concerns over bleeding after biopsy or polypectomy.

To determine whether patients using the NSAID nabumetone, a non-acidic prodrug with mixed activity against cyclooxygenase-1 (COX-1) and COX-2, exhibited prolonged mucosal bleeding times and how this might compare with mucosal bleeding times in patients using aspirin.

We assessed triplicate mucosal bleeding times in patients undergoing screening flexible sigmoidoscopy. We compared 90 patients who had taken no aspirin or NSAIDs within the previous 2 weeks, to 60 patients who had received nabumetone 1 g b.d. by mouth for the previous 2 weeks, and 30 patients who had taken 325 mg aspirin daily for the previous 2 weeks. In each case, the investigator performing the study was blinded to the patient's medication.

Mucosal bleeding times did not differ significantly among control or nabumetone-using patients. However, the patients receiving aspirin exhibited significant prolongation. Mucosal bleeding time correlated statistically significantly, but weakly, with skin bleeding time.

Nabumetone does not appear to prolong mucosal bleeding time after mucosal pinch biopsy, and skin bleeding time does not reliably screen for prolonged mucosal bleeding time.