Bivalirudin
Angiomax
Parenteral direct thrombin inhibitor (DTI)
Directly, reversibly inhibits thrombin. Short half-life; predictable. Used in PCI and as a heparin alternative in HIT.
Indications
- •PCI (esp. HIT)
- •HIT anticoagulation
- •Alternative to heparin in cardiac surgery when HIT
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| PCI | 0.75 mg/kg IV bolus, then 1.75 mg/kg/hr infusion | — |
| HIT | 0.15–0.2 mg/kg/hr IV, titrate to aPTT | — |
Pharmacokinetics
Onset immediate. Half-life ~25 min (longer in renal impairment). ~20% renal, rest enzymatic (proteolysis) — good if both organ systems marginal.
Side effects
- !Bleeding (less than heparin + GP IIb/IIIa in some PCI trials)
Contraindications
- ×Active major bleeding
Reversal / antidote
No specific antidote; short half-life — stop infusion; hemofiltration partially removes
Clinical pearls
- ★ASRA neuraxial: DTIs — neuraxial avoided while anticoagulated (no consensus interval).
- ★Predictable short half-life makes it convenient for cath-lab use.
- ★Enzymatic clearance means less accumulation than argatroban in combined organ failure.
Other drugs in Coagulation Related
- Heparin (unfractionated)
Activates antithrombin → inactivates IIa (thrombin) and Xa.
- Tranexamic Acid (TXA)
Reversibly binds plasminogen, blocking conversion to plasmin → preserves fibrin clot.
- Protamine Sulfate
Strongly basic (positive-charge) protein binds to highly acidic (negative-charge) heparin → inactive ionic complex → renal excretion. 1 mg protamine neutralizes ~100 units heparin.
- DDAVP (Desmopressin)
Selective V2 agonist (renal water retention + Factor VIII/vWF release from endothelial Weibel-Palade bodies). NO V1 vasopressor activity at therapeutic dose.
- Warfarin
Inhibits vitamin K epoxide reductase (VKORC1) → depletes reduced vitamin K → ↓ synthesis of factors II, VII, IX, X and proteins C/S. Full effect takes days (waits for existing factor decay).
- Enoxaparin
Antithrombin-mediated inhibition, weighted toward factor Xa over IIa (~3.8:1). More predictable than UFH — no routine monitoring.
- Dalteparin
Antithrombin-mediated factor Xa > IIa inhibition. Similar profile to enoxaparin; preferred LMWH in cancer-associated VTE (CLOT trial).
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
- •ASRA regional anesthesia in the anticoagulated patient guidelines, 2018
