Cyclo-oxygenase-2 inhibitors were found to be no safer than nonselective NSAIDs in averting adverse gastrointestinal events in a large observational study in the United Kingdom.
The finding is important “given that enhanced gastrointestinal safety has been one of the main justifications for these drugs,” wrote Dr. Julia Hippisley-Cox and her associates at the University of Nottingham (England).
They also found that the concomitant use of ulcer-healing drugs reduces the GI risks of COX-2 inhibitors, which suggests “there is some risk to protect against.” Taken together, these results indicate that COX-2 inhibitors “may not be as safe as originally thought,” the authors said (BMJ 2005;331:1310–6).
The COX-2 inhibitors were developed to relieve pain without inducing the GI side effects common with NSAIDs, but data on their long-term safety are lacking. The University of Nottingham researchers calculated the comparative risks of GI events in patients who took these prescription pain relievers between 2000 and 2004.
After reviewing the medical records in a database of more than 7 million patients treated at general practices throughout England, Scotland, and Wales, the investigators identified 9,407 who had an adverse GI event and matched them with more than 88,000 controls who had no such events. Patients with GI events were more likely to have taken either prescription NSAIDs (odds ratio 1.69) or prescription COX-2 inhibitors (OR 1.89) than were control subjects.
Celecoxib was the only agent out of 27 pain relievers used by the study subjects to show no link with adverse GI events. However, the number of celecoxib users was small, so this finding remains “difficult to interpret,” they noted.
Use of ulcer-healing drugs such as proton pump inhibitors cut the risk for GI events in users of both COX-2 inhibitors and NSAIDs, again suggesting that the GI risks of the two types of pain relievers are similar, the authors wrote.