Parental anticoagulants for the management of HIT
| . | Indirect factor Xa inhibitors . | Direct thrombin inhibitors . | |||
|---|---|---|---|---|---|
| Fondaparinux . | Danaparoid . | Argatroban . | Bivalirudin . | Desirudin . | |
| Administration | Subcutaneous injection | IV infusion or subcutaneous injection | Continuous IV infusion | Continuous IV infusion | Subcutaneous injection |
| Clearance (half-life) | Renal (17 h) | Renal (24 h) | Hepatobiliary (40-50 min) | Renal/enzymatic (25 min) | Renal (2 h) |
| INR interference | No | No | Yes | Yes | Possible |
| Drug monitoring | None* | Anti-Xa activity* | PTT | PTT | None |
| Reversal agent | None† | None† | None | None | None |
| Other | Caution with renal impairment. Contraindicated with CrCl <30 mL/min | Caution with renal impairment; not available in the United States | Caution with liver dysfunction; consider dose reduction in critically ill patients | Evidence for use available in cardiac surgery and PCI | Caution with renal impairment |
| . | Indirect factor Xa inhibitors . | Direct thrombin inhibitors . | |||
|---|---|---|---|---|---|
| Fondaparinux . | Danaparoid . | Argatroban . | Bivalirudin . | Desirudin . | |
| Administration | Subcutaneous injection | IV infusion or subcutaneous injection | Continuous IV infusion | Continuous IV infusion | Subcutaneous injection |
| Clearance (half-life) | Renal (17 h) | Renal (24 h) | Hepatobiliary (40-50 min) | Renal/enzymatic (25 min) | Renal (2 h) |
| INR interference | No | No | Yes | Yes | Possible |
| Drug monitoring | None* | Anti-Xa activity* | PTT | PTT | None |
| Reversal agent | None† | None† | None | None | None |
| Other | Caution with renal impairment. Contraindicated with CrCl <30 mL/min | Caution with renal impairment; not available in the United States | Caution with liver dysfunction; consider dose reduction in critically ill patients | Evidence for use available in cardiac surgery and PCI | Caution with renal impairment |
CrCl, creatinine clearance; PCI, percutaneous coronary intervention.
Some centers monitor fondaparinux using fondaparinux-specific anti-Xa activity. Some centers do not routinely monitor danaparoid, particularly in patients with normal renal function.93
Andexanet alfa is a reversal agent for direct and indirect Xa inhibitors but has not been studied or approved for use in HIT or with reversal of fondaparinux or danaparoid. Given the potential risk of ischemic events with andexanet alfa, caution in HIT is needed.