Antidepressant-Warfarin Interaction and Gastrointestinal Bleeding Risk
Author Information
Author(s): Hedi Schelleman, Colleen M. Brensinger, Warren B. Bilker, Sean Hennessy
Primary Institution: University of Pennsylvania School of Medicine
Hypothesis
Does the initiation of an antidepressant increase the risk of hospitalization for gastrointestinal bleeding in warfarin users?
Conclusion
Warfarin users who started certain antidepressants had a higher risk of hospitalization for gastrointestinal bleeding.
Supporting Evidence
- The incidence rate of hospitalization for GI bleeding among warfarin users was 4.48 per 100 person-years.
- Citalopram, fluoxetine, paroxetine, and amitriptyline were associated with increased odds of GI bleeding.
- Mirtazapine, which is not believed to interact with warfarin, also increased the risk of GI bleeding.
Takeaway
If someone is taking a blood thinner called warfarin and starts taking an antidepressant, they might be more likely to have stomach bleeding.
Methodology
An observational case-control study using Medicaid claims data from 1999 to 2005, analyzing warfarin users aged 18 and older.
Potential Biases
Possible unmeasured confounding factors affecting the results.
Limitations
Potential residual confounding by unmeasured factors such as depression severity and limited number of individuals initiating antidepressant therapy.
Participant Demographics
Warfarin users aged 18 and older, with a significant portion being elderly and having comorbid conditions.
Statistical Information
P-Value
p<0.05
Confidence Interval
95% CI, 4.42–4.55
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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