Risks of clinically significant upper gastrointestinal events with etodolac and naproxen: a historical cohort analysis

Etodolac is a generic nonsteroidal anti-inflammatory drug (NSAID). Previous in vitro studies have shown that etodolac is a selective inhibitor of cyclooxygenase (COX)-2 with selectivity in between that of other COX-2 inhibitors such as celecoxib and rofecoxib. However, there are no outcomes data assessing clinically significant upper gastrointestinal (CSUGI) events with etodolac.

A historical cohort study was performed at the Dallas Veterans Affairs Medical Center in which 16,286 veteran patients (5596 patient-years) received etodolac or naproxen during a 3-year period without concurrent use of other ulcerogenic drugs other than low-dose aspirin. The primary outcome was the CSUGI event rate of the etodolac and naproxen groups without concomitant low-dose aspirin.

The incidence of CSUGI events was .78% and .24% for naproxen and etodolac, respectively. In the NSAID-naive subset, the incidence of CSUGI events was .99% and .24% for naproxen and etodolac, respectively. Compared with naproxen, etodolac was associated with a reduction in upper gastrointestinal events, corresponding to an odds ratio of .39 (95% confidence interval, .20-.76; P = .006). Concomitantly used low-dose aspirin increased event rates with naproxen 2-fold and etodolac 9-fold. Hence, there was no significant difference in gastrointestinal event rates between etodolac and naproxen when low-dose aspirin was taken concomitantly.

Etodolac is a generic COX-2 selective inhibitor that reduces CSUGI events compared with the nonselective NSAID naproxen. However, concomitant use of low-dose aspirin negates the gastrointestinal safety advantages of etodolac.