ACUTE ANTICOAGULATION 

Table 10. Indications for Anticoagulation in the Absence of Active Bleeding or Severe Bleeding Risk Condition Target INR Duration of Therapy Hip or major knee surgery 2.0–3.0 7–10 d or until patient is ambulatory Idiopathic venous thromboembolism (includes PE) 2.0–3.0 First 3 mo   1.5–3.0 3 mo–indefinitely Atrial fibrillation 2.0–3.0 Indefinitely Mitral valvular heart disease with hx of systemic embolization or left atrial diameter >5.5 cm 2.0–3.0 Indefinitely Cardiomyopathy with EF <25% 2.0–3.0 Indefinitely Mechanical aortic valve with normal left atrial size and sinus rhythm 2.0–3.0* Indefinitely Mechanical aortic valve with enlarged left atrium and/or atrial fibrillation 2.5–3.5*† Indefinitely Mechanical mitral valve 2.5–3.5*† Indefinitely Caged ball or caged disk valve 2.5–3.5‡ Indefinitely Bioprosthetic heart valve 2.0–3.0 3 mo Acute MI complicated by severe left ventricular dysfunction, HF, previous emboli, mural thrombus on echocardiography 2.0–3.0 1–3 mo *  If additional risk factors are present or if there is systemic embolism despite anticoagulation treatment, target INR is 2.5–3.5 and ASA 80–100 mg/d should be added. †  Alternative target INR 2.0–3.0 with addition of ASA 80–100 mg/d. ‡  With addition of ASA 80–100 mg/d.

Table 11. Treatment of Warfarin Overdose INR Clinical Situation Action ≥3.5 and <5.0 No significant bleeding Omit next warfarin dose and/or lower dose ≥5.0 and <9.0 No significant bleeding Omit next 1–2 doses of warfarin and restart therapy at lower dose; alternatively, omit 1 dose and give VK 1.0–2.5 mg po ≥9.0 No significant bleeding D/C warfarin and give VK 3.0–5.0 mg po; give additional VK po if INR is not substantially reduced in 24–48 h. Restart warfarin at lower dose when INR is therapeutic. ≥3.0 and <20.0 Serious bleeding D/C warfarin; give VK 1.0–10.0 mg by slow IV infusion, supplemented with fresh frozen plasma or prothrombin complex concentrate depending on urgency of situation; check INR q 6h; repeat VK q 12 h as needed Any elevation Life-threatening bleeding D/C warfarin; give VK 10.0 mg by slow IV infusion, supplemented with prothrombin complex concentrate; repeat this treatment as needed Note: VK = vitamin K. Source: Data from American College of Chest Physicians Consensus Panel on Antithrombotic Therapy: Ansell J, Dalen J, Anderson D, et al. Managing oral anticoagulant therapy. In: Sixth ACCP Consensus Conference on Antithrombotic Therapy. Chest. 2001; 119(1 Suppl):22S–38S.

WARFARIN THERAPY 

Table 12. Anticoagulants for DVT or PE Prophylaxis and Treatment Class, Agent DVT or PE Prophylaxis Dosage By Condition Type DVT or PE Treatment Dosage Comments Heparin       Unfractionated heparin (Hep-Lock) General surgery: 5000 U SC 2 h before and q 12 h after surgery 5000 U/kg IV bolus followed by 15 mg/kg/h IV* Bleeding, anemia, thrombocytopenia, hypertransaminase- mia, urticaria (L, K) LMWH       Enoxaparin (Lovenox) THA, HFX: 30 mg SC q 12 h or 40 mg SC qd KR: 30 mg SC q 12 h; AS: 40 mg SC qd Outpatient treatment of DVT: 1 mg/kg SC q 12 h; inpatient treatment of DVT ± PE: 1 mg/kg SC q 12 h or 1.5 mg/kg SC qd* Bleeding, anemia, hyperkalemia, hyper- transaminasemia, thrombocytopenia, thrombocytosis, urticaria, angioedema (K) Dalteparin (Fragmin) Low-risk THA: 2500–5000 U SC before surgery, 5000 U SC qd after surgery Abdominal surgery: 2500–5000 U SC before and after surgery DVT: 100 U/kg SC q 12 h; also indicated for anticoagulation in acute coronary syndrome Same (K) Tinzaparin (Innohep) NA 175 anti-Xa IU/kg SC qd* Same (K) Heparinoid       Danaparoid (Orgaran) THA, HFX, HIT: 750 anti-Xa U SC bid NA Same as LMWH (K) Factor Xa Inhibitor     Fondaparinux (Arixtra) THA, HFX, KR: 2.5 mg SC qd beginning 6–8 h after surgery Weight <50 kg: 5 mg SC qd; weight 50–100 kg: 7.5 mg SC qd; weight >100 kg: 10 mg SC qd Contraindicated if CrCl <30 mL/min (K) Direct Thrombin Inhibitors     Argatroban HIT: 2 μg/kg/min IV infusion HIT: 2 μg/kg/min IV infusion ↓ dosage if hepatic impairment (L) Lepirudin (Refludan) HIT: 4 mg/kg bolus, then 0.15 mg/kg/h HIT: 4 mg/kg bolus, then 0.15 mg/kg/h ↓ bolus to 0.2 mg/kg if CrCl <60 Thrombolytics       Streptokinase (Kabikinase, Streptase) NA 250,000 U IV over 30 min, then 100,000 U/h for 24 h† Risk of hemorrhage ↑ with age and higher BMI; HTN, hallucination, agitation, confusion, serum sickness (L) Note: THA = total hip arthroplasty (hip replacement); HFX = hip fracture surgery; KR = knee replacement; HIT = heparin-induced thrombocytopenia; NA = not applicable. * Also indicated for anticoagulation in acute coronary syndrome (see Table 14). † Dose in acute MI is 1.5 million U IV over 60 min.

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