Table 1.
Pharmacology of Commonly Used Anticoagulants*
| Agent | Half-Life | Monitoring Serum Test | Reversal Agent |
|---|---|---|---|
| Warfarin (Coumadin®) | 40 hours | INR | Fresh frozen plasma |
| Unfractionated heparin | 1.5 hours | aPTT, ACT | Protamine (1 mg/100 IU) |
| LMWH: Enoxaparin (Lovenox®) | 4.5–7 hours | Anti-Xa | Incomplete. Protamine (1 mg/1 mg enoxaparin); repeat at half dose if needed. |
| LMWH: Dalteparin (Fragmin®) | 2–5 hours | Anti-Xa | Incomplete. Protamine (1 mg/100 IU); repeat at half dose if needed. |
| LMWH: Tinzaparin (INNOHEP®) | 3–4 hours | Anti-Xa | Incomplete. Protamine (1mg/100 IU); repeat at half dose if needed. |
| Fondaparinux (Arixtra®) | 17 hours | Anti-Xa | None. Consider recombinant factor VIIa. |
| Bivalirudin (Angiomax®) | 25 minutes | aPTT | None. Consider recombinant factor VIIa. |
| Argatroban | 45 minutes | aPTT | None. Consider recombinant factor VIIa. |
INR, international normalized ratio; aPTT, activated partial thromboplastin time; ACT, activated clotting time; LMWH, low-molecular-weight heparin.
Adapted from Hirsh et al1.
*
In consideration of pre/periprocedural anticoagulation, elimination of the agent is of primary concern. In general, five half-lives are required for complete elimination of a substance. If the procedure must be performed before that time frame, reversal agents are listed for reference.