Direct oral anticoagulants are preferred for most; tailor to renal function, cancer status, and bleeding risk.
DOAC options (adult, typical renal function)
Apixaban: 10 mg BID × 7 days, then 5 mg BID; extended prevention 2.5 mg BID after ≥6 months [1], [2].
Rivaroxaban: 15 mg BID × 21 days, then 20 mg daily with food; extended 10 mg daily after ≥6 months [1], [2].
Dabigatran: 150 mg BID after 5–10 days parenteral lead-in [2].
Edoxaban: 60 mg daily (reduce to 30 mg if CrCl 15–50 mL/min or weight ≤60 kg) after 5–10 days parenteral lead-in [2].
Treatment phases
Initial: first 5–21 days; rapid full-dose anticoagulation.
Primary treatment: complete 3 months for all confirmed VTE [1], [2].
Extended: beyond 3 months for unprovoked or persistent risk factors; consider reduced-dose DOAC to lower bleeding risk while maintaining protection [1], [2].
When warfarin or heparin is preferred
Antiphospholipid syndrome: warfarin (INR 2–3) preferred over DOACs [2].
Severe renal failure (CrCl <15–30 mL/min depending on agent), extremes of body weight, or cost barriers.
Pregnancy: use LMWH; avoid DOACs [2].
High bleeding risk strategies
Choose apixaban or reduced-dose regimens for extended therapy when appropriate [1], [2].
Gastroprotection with PPIs for GI bleed risk; avoid dual antiplatelet therapy unless clearly indicated.
IVC filter only if acute VTE with absolute contraindication to anticoagulation; remove when anticoagulation becomes feasible [1].
Cancer-associated VTE
DOACs (apixaban, rivaroxaban, edoxaban) or LMWH are effective; individualize by bleeding risk (e.g., GI/GU cancer) and drug–drug interactions [8].
Continue anticoagulation for at least 3–6 months and as long as cancer is active or anticancer therapy continues [8].
Recurrent VTE on anticoagulation
Confirm true recurrence by comparing prior and current imaging; residual thrombosis is common [7].
Assess adherence, drug interactions, dosing errors, and absorption issues first [7].
If confirmed on DOAC with good adherence, switch to therapeutic LMWH or increase intensity per specialist guidance [7].