Betrixaban and Venlafaxine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Venlafaxine
No brand names on recordBetrixaban
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of bleeding
Interaction Deep Dive
Case reports and epidemiological studies have shown that use of selective serotonin reuptake inhibitors (SSRIs) and serotonin norephinephrine reuptake inhibitors (SNRIs), including venlafaxine, is associated with gastrointestinal bleeding. Bleeding events with SSRIs and SNRIs included cases of ecchymoses, hematomas, epistaxis, and petechiae; life-threatening hemorrhages have also occurred. Coadministration with anticoagulants may potentiate the risk of bleeding. A population-based, case-controlled study of new coumarin users (acenocoumarol and phenprocoumon) with concomitant selective serotonin reuptake inhibitors (SSRIs) resulted in an increased risk of hospitalization due to non-gastrointestinal bleeding1. Concomitant use of venlafaxine with an anticoagulant drug may potentiate the risk of bleeding. Closely monitor for bleeding for patients receiving an anticoagulant drug when venlafaxine is initiated or discontinued 2.
Why it happens (mechanism)
Additive effects on hemostasis
Literature reports
1 report — tap to read
a) A population-based, case-controlled study of new coumarin users (acenocoumarol and phenprocoumon) with concomitant selective serotonin reuptake inhibitors (SSRIs) resulted in an increased risk of hospitalization due to non-gastrointestinal bleeding. Using national pharmacy and hospitalization records, Netherlands researchers identified 1848 cases that were admitted for abnormal bleeding and compared them with 5818 control subjects also taking coumarins. Median duration of treatment in patients was 220 days (range, 1 to 4690 days). Patients on SSRIs showed greater risk for hospitalization for non-gastrointestinal bleeding (adjusted odds ratio (OR) 1.7, 95% confidence interval (CI), 1.1 to 2.5), however, the rate of gastrointestinal bleeding (adjusted OR 0.8, 95% CI, 0.4 to 1.5) was not significantly different 1.
Common questions
Can I take Betrixaban and Venlafaxine together?
An increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Betrixaban and Venlafaxine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Betrixaban or Venlafaxine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Schalekamp T, Klungel OH, Souverein PC, et al: Increased bleeding risk with concurrent use of selective serotonin reuptake inhibitors and coumarins. Arch Intern Med 2008; 168(2):180-185. DOI
- Product Information: EFFEXOR XR(R) oral extended-release capsules, venlafaxine oral extended-release capsules. Viatris Specialty (per FDA), Morgantown, WV, 2023. DailyMed
Keep reading about Venlafaxine
Keep reading about Betrixaban
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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