Medications that often increase bleeding risk
- NSAIDs (ibuprofen, naproxen) — GI bleeding risk
- Antiplatelets (aspirin, clopidogrel) — additive effect
- SSRIs/SNRIs (some antidepressants) — may increase bleeding tendency
- Systemic steroids — can increase GI risk when combined with NSAIDs
This is not a complete list. Always check with your clinician/pharmacist before starting a new medication.
Drug–drug interactions (especially for DOACs)
Some medicines change DOAC levels via P-gp and/or CYP3A4 pathways.
- Stronger inhibitors can raise DOAC levels (higher bleeding risk).
- Strong inducers can lower DOAC levels (higher clot risk).
If you are prescribed antibiotics/antifungals, seizure medications, HIV meds, or some heart rhythm drugs—ask specifically about anticoagulant interactions.
Herbs and supplements (common culprits)
“Natural” does not mean “risk-free.” Some supplements can increase bleeding or interact with warfarin.
- St. John’s wort (can reduce some DOAC levels; also affects warfarin)
- Ginkgo, garlic, high-dose fish oil (may increase bleeding tendency)
- Vitamin K supplements and large diet changes (important for warfarin)
Warfarin tip: Aim for a consistent intake of vitamin K-containing foods. Sudden changes can alter INR.