Table 1.
Characteristics of altenative anticoagulants.
| Agent | Class | Dose | Therapy Goal | Excretion | T1/2 | Antagonist | Comments |
|---|---|---|---|---|---|---|---|
| Lepirudin | Irreversible direct thrombin inhibitor | .4 mg/kg IV bolus (up to 110 kg) followed by .14 mg/kg/h | Target aPTT of 1.5–2.5 times the median normal range | Renal | 90 minutes (depends on renal function) | None | Yeast derived recombinant hirudin; Anaphylaxis after reexposure has been reported; Crosses placenta in animal studies |
| Argatroban | Reversible direct thrombin inhibitor | 2 mcg/mg/kg initial IV continues infusion; No bolus is indicated; Not to exceed 10 mcg/kg/min | Target aPTT of 1.5–3 times the initial baseline | Hepatic | 40–50 minutes (depends on hepatic function) | None | Reduced the relative risk of death, new thrombosis, or other complications in patients with HIT in clinical trials; Before administration discontinue heparin and obtain baseline aPTT; Interferes with fibrin generation, platelet aggregation, and factor XII activation Increases in a dose-dependent manner, aPTT, the ACT, the PT, the INR and the thrombin time |
| Bivalirudin | Reversible direct thrombin inhibitor | .75 mg/kg IV bolus followed by 1.75 mg/kg/h | N/A | Renal, proteolytic cleavage | 25 minutes | None | SC/IV; Interferes with fibrin generation, platelet aggregation and factor XII activation |
| Danaparoid | Heparinoid, selective inhibitor of anti-factor Xa | 30 units/kg IV loading dose then 1.2–2 units/kg/h IV maintenance dose | Target anti-Xa activity of .4–.8 units/mL | Renal | 24 hours | Protamine does not reverse the bleeding effects | SC/IV; Obtained from porcine intestinal mucosa after the removal of heparin; Heparan sulfate binds to antithrombin III to inactivate factor Xa and to a much lesser extent, factor IIa; Dermatan sulfate activates heparin cofactor II which acts on factor IIa (thrombin) |
| Fondaparinux | Indirect factor Xa inhibitor | 5 mg (<50 kg), 7.5 mg (50–100 kg), 10 mg (>100 kg) SC on prescription | Does not require laboratory monitoring | Renal | 18 hours | None | Selectively inhibits factor Xa via antithrombin-dependent actions; Does not inhibit thrombin (factor IIa); Depends on antithrombin III for activity |
| Melagatran Ximelagatran | Direct thrombin inhibitor | The expected labeled dosage is unclear at this time | Does not require laboratory monitoring | N/A | 6 hours | None | SC/PO; Rapid onset of severe liver injury was reported |
Data taken from the website http://druginfo.goldstandard.com.
aPTT, activated partial thromboplastin time; PT, prothrombin time; INR, international standardized ratio; SC, subcutaneous; PO, per oss; IV, intravenous; T1/2, half life.