Dose of selective serotonin reuptake inhibitors and risk of upper gastrointestinal bleeding in older adults

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) have been associated with an increased risk of upper gastrointestinal bleeding (UGIB) in older patients but little is known about the risk associated with individual SSRI drugs and doses. AIMS: To quantify the risk of UGIB in relation to individual SSRI use in older adults. METHODS: We conducted a nested case-control study within a cohort of 9565 patients aged ⩾65 years prescribed SSRIs from 2000 to 2013 using claims data of universal health insurance in Taiwan. Incident cases of UGIB during the follow-up period were identified and matched with three control subjects. Conditional logistic regression was used to estimate the odds ratio (OR) of UGIB associated with individual SSRI use and cumulative dose. RESULTS: UGIB risk increased with the increasing cumulative doses of SSRIs (adjusted OR: 1.28, 95% confidence interval (CI): 1.02-1.62 for the highest vs. the lowest tertile). Compared with users of other SSRIs, fluoxetine users were at an increased risk of UGIB (adjusted OR: 1.25, 95% CI: 1.03-1.50) with a dose-response manner, whereas paroxetine users had 29% decreased odds (95% CI: 0.56-0.91). The increased risk was only observed among current fluoxetine users. CONCLUSIONS: Fluoxetine therapy was associated with an increased risk of UGIB in a dose-response manner among older adults.