Cyclooxygenase-2 inhibitors were found to be no safer than nonselective NSAIDs in averting adverse gastrointestinal events in a large observational study conducted 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). The COX-2 inhibitors were developed to relieve pain without inducing the GI side effects common with NSAIDs, but long-term safety data are lacking.
The researchers calculated the risk 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 (BMJ 2005;331:1310–6).
Patients with GI events were more likely to have taken either prescription NSAIDs (odds ratio 1.69) or prescription COX-2 inhibitors (odds ratio 1.89) than were control subjects.
The researchers also found that the concomitant use of ulcer-healing drugs reduces the GI risks of COX-2 inhibitors, which suggests “that 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.
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 very small, so this finding remains “difficult to interpret,” the researchers noted.
The use of ulcer-healing drugs such as proton pump inhibitors reduced 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, they added.