Anticoagulant agents: relevant information for perioperative management of anticoagulant agents2-5
| Anticoagulant therapy . | Primary mode of action . | Time to maximum effect . | Elimination half-life . | Notes . |
|---|---|---|---|---|
| Warfarin (racemic) | Inhibition of vitamin K–dependent γ-carboxylation | 90 min for circulating drug; ∼ 5-7 d for a therapeutic INR | 36-42 h for circulating drug; ∼ 5 d to normalize INR | Anticoagulant effect reflects alterations in circulating vitamin K–dependent factors (II, VII, IX, X), which varies from hours (factor VII) to days (factor II) |
| Unfractionated heparin | AT-mediated inhibition of serine proteinases | Immediate (intravenous); within 6 h (subcutaneous) | 30-60 min | Effective reversal with protamine |
| Low-molecular weight heparin | AT-mediated serine proteinase inhibition | 3-5 h | 3-6 h | Renal clearance with prolonged elimination in renal failure; partial reversal with protamine |
| Fondaparinux | AT-mediated inhibition of Factor Xa | ∼ 2 h | 17 h | Renal clearance with prolonged clearance in renal failure; not reversed by protamine |
| Dabigatran | Direct thrombin inhibition | 1.25-3 h | 12-14 h | Nonreversible; 80% renal clearance with prolonged elimination with renal insufficiency |
| Rivaroxaban | Direct factor Xa inhibition | 2-4 h | 9-13 h | Nonreversible; 66% renal clearance |
| Apixaban* | Direct factor Xa inhibition | 1-3 h | 8-15 h | Nonreversible; ∼ 25% renal clearance |
| Anticoagulant therapy . | Primary mode of action . | Time to maximum effect . | Elimination half-life . | Notes . |
|---|---|---|---|---|
| Warfarin (racemic) | Inhibition of vitamin K–dependent γ-carboxylation | 90 min for circulating drug; ∼ 5-7 d for a therapeutic INR | 36-42 h for circulating drug; ∼ 5 d to normalize INR | Anticoagulant effect reflects alterations in circulating vitamin K–dependent factors (II, VII, IX, X), which varies from hours (factor VII) to days (factor II) |
| Unfractionated heparin | AT-mediated inhibition of serine proteinases | Immediate (intravenous); within 6 h (subcutaneous) | 30-60 min | Effective reversal with protamine |
| Low-molecular weight heparin | AT-mediated serine proteinase inhibition | 3-5 h | 3-6 h | Renal clearance with prolonged elimination in renal failure; partial reversal with protamine |
| Fondaparinux | AT-mediated inhibition of Factor Xa | ∼ 2 h | 17 h | Renal clearance with prolonged clearance in renal failure; not reversed by protamine |
| Dabigatran | Direct thrombin inhibition | 1.25-3 h | 12-14 h | Nonreversible; 80% renal clearance with prolonged elimination with renal insufficiency |
| Rivaroxaban | Direct factor Xa inhibition | 2-4 h | 9-13 h | Nonreversible; 66% renal clearance |
| Apixaban* | Direct factor Xa inhibition | 1-3 h | 8-15 h | Nonreversible; ∼ 25% renal clearance |
AT indicates antithrombin; INR, international normalized ratio.
Apixaban currently is not available for clinical use in the United States.