CriticalDirect oral anticoagulants (factor Xa inhibitors)×Vitamin K antagonist anticoagulants
Updated · Methodology
Mechanism
Warfarin blocks vitamin K-dependent clotting factor synthesis; rivaroxaban directly inhibits factor Xa. Effects are additive with risk of major bleeding.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage, gross haematuria with renal colic, spontaneous retroperitoneal haematomas. Symptoms may appear within days of co-prescription.
Management
The combination is not prescribed. Switching from warfarin to rivaroxaban: stop warfarin, wait for INR below 3.0, then start rivaroxaban. Reverse switch: overlap with INR monitoring, stop rivaroxaban once INR exceeds 2.0.
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: Xarelto (rivaroxaban) prescribing information (2011)– ; DailyMed setid 10db92f9-2300-4a80-836b-673e1ae91610
- EMA: Ficha técnica: Rivaroxabán (EU/1/08/472), sección 4.3 (2026)– EMA SmPC vía AEMPS CIMA, nº 08472018 (EU/1/08/472), sección 4.3, consultado 10/2026