Major
duloxetine × Warfarin
SNRI×Vitamin K antagonist anticoagulants
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. PPI cover with pantoprazole is mandatory. Check INR at 2 and 4 weeks after starting duloxetine, then monthly. Alternative antidepressants with minimal platelet effect: mirtazapine or agomelatine.
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.