Difference in risk of gastrointestinal complications between users of enteric-coated and buffered low-dose aspirin

Difference in the risk of gastrointestinal (GI) complications between users of enteric-coated and buffered low-dose aspirin (LDA) is unclear. The purpose of the study is to examine the difference in risk of GI damage between enteric-coated and buffered LDA products.

A large and chronologically organized receipt database constructed by a database vendor was utilized. Prescription and event sequence symmetry analysis was used to identify the risk of LDA-induced GI complications over the period from January 2005 to July 2011. LDA use in combination with H2-receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) was examined by prescription sequence symmetry analysis. Likewise, symmetry analysis was undertaken to evaluate the association between the diagnosis of GI disease and the prescription of LDA products.

In July 2011, enteric-coated LDA users were more frequently co-administered PPIs than buffered LDA users (25.4% vs. 14.4%). Prescription sequence symmetry analysis of acid inhibitor use found no significant associations with enteric-coated LDA use and buffered LDA use. The event sequence symmetry analysis of ulcer, gastritis and duodenitis, and melena found significant associations with entericcoated LDA use, with adjusted sequence ratios (ASRs) of 1.58 (1.23 - 2.06), 1.30 (1.03 - 1.65), and 14.38 (2.19 - 607.95), respectively, at the 6-month interval. At the 12-month interval, analysis of ulcers and melena found significant associations for enteric-coated LDA users, with ASRs of 1.39 (1.13 - 1.73) and 20.83 (3.33 - 863.25), respectively.

Our findings do not support that there is no difference in the risk of GI complications between enteric-coated LDA and buffered LDA, but rather may imply that the risk of GI complications associated with enteric-coated LDA is higher than that with buffered LDA.