Observational study of upper gastrointestinal tract bleeding events in patients taking duloxetine and nonsteroidal anti-inflammatory drugs: a case-control analysis

PURPOSE To determine whether the concomitant use of duloxetine with prescription nonsteroidal anti-inflammatory drugs (NSAIDs) or aspirin was associated with an increased risk for upper gastrointestinal (UGI) bleeding compared with taking these analgesics alone. METHODS Truven Health Analytics MarketScan Research Databases were examined for hospital admissions of adult patients indexed from January 1, 2007-December 31, 2011. Cases were patients with UGI hemorrhage or peptic ulcer disease. Controls were randomly selected from the remaining admissions to match 10:1 with cases based on age, sex, and admission date. Prescription medication exposure groups of interest were: 1) no exposure to duloxetine, NSAIDs or aspirin; 2) duloxetine only; 3) NSAIDs or aspirin only; 4) duloxetine plus NSAIDs or aspirin. Logistic regression and relative excess risk due to interaction was utilized to estimate any increased risk of UGI bleeding for patients prescribed these medications across these groups. RESULTS There were 33,571 cases and 335,710 controls identified. Comparing exposure group 2 and group 4, the adjusted odds ratio was 1.03 (95% confidence interval [CI], 0.94, 1.12), and the adjusted relative excess risk due to interaction was 0.352 (95% CI: -0.18, 0.72) for risk of UGI bleeding, neither of which support an increased risk or an interaction between duloxetine and prescription NSAID or aspirin for these events. CONCLUSION There was no evidence of an increased risk for UGI bleeding when duloxetine was taken with prescription NSAIDs or aspirin. In addition, there was no evidence of an interaction between duloxetine and prescription NSAIDs or aspirin for an increased risk of these events.