MajorSNRI×Vitamin K antagonist anticoagulants
Updated · Methodology
Mechanism
Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI). It depletes the platelet serotonin pool, impairing primary haemostasis. On warfarin, upper GI bleeding risk roughly doubles.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage. Risk rises in patients over 65 and with prior peptic ulcer disease.
Management
The combination is acceptable with coagulation monitoring. Check the INR more often than usual after duloxetine is started or stopped, until values are stable. Tell the patient to report bruising without injury, bleeding gums, black stools or blood in the urine. Bleeding risk rises further if NSAIDs or aspirin are added, and the duloxetine label calls for caution in that case.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Cymbalta (duloxetine delayed-release capsules) – Prescribing Information (2025)– FDA, DailyMed SPL, Eli Lilly and Company, разделы 5.5 и 7.4
- EMA: Cymbalta 30 mg cápsulas duras gastrorresistentes – ficha técnica (texto EMA en CIMA) (2026)– EMA SmPC vía AEMPS CIMA, nº 04296001 (EU/1/04/296), secciones 4.4 y 4.5
- FDA: Jantoven (warfarin sodium tablets) – Prescribing Information (2025)– FDA, DailyMed SPL, Upsher-Smith Laboratories, разделы 5.1, 7.1 и 7.3