Initial anticoagulation options for-venous thromboembolism

(EHJ 2020;41:543; Chest 2021;160:e545)

• Initiate immediately if high or intermed suspicion but dx test results will take ≥4 h

• Either (a) initial parenteral → long-term oral or (b) solely DOAC if no interven. planned

LMWH

• (eg, enoxaparin 1 mg/kg SC bid or dalteparin 200 IU/kg SC qd)

Preferred over UFH (especially in cancer) except:

* renal failure (CrCl <25),
* ? extreme obesity
* hemodynamic instability or bleed risk (Cochrane 2004;CD001100)

IV UFH:

• 80 U/kg bolus → 18 U/kg/h → titrate to PTT 1.5–2.3 × cntl (eg, 60–85 sec);

• preferred option when contemplating thrombolysis or catheter-based Rx (qv)

• IV direct thrombin inhibitors (eg, argatroban, bivalirudin) used in HIT ⊕ Pts

Fondaparinux:

• 5–10 mg SC qd (NEJM 2003;349:1695);i
• use if HIT ⊕;
• avoid if renal failure

Direct oral anticoag

• (DOAC; NEJM 2010;363:2499; 2012;366:1287; 2013;369:799 & 1406)
• Preferred b/c as good/better than warfarin in preventing recurrent VTE w/ less bleeding
• Apixaban (10 mg bid × 7 d → 5 bid) or
• rivaroxaban (15 mg bid for 1st 3 wk → 20 mg/d) can be given as sole anticoagulant w/ initial loading dose
• Edoxaban or dabigatran can be initiated after ≥5 d of parenteral anticoag

DVT & low-risk PE w/o comorbidities and able to comply with Rx can be treated as outPt

Generally safe to anticoagulate

• if platelets >50,000 but contraindicated if <20,000