Factor VIII Concentrate
Advate · Kogenate · Humate-P (with vWF)
Antihemophilic factor (recombinant or plasma-derived)
Replaces deficient factor VIII → restores intrinsic-pathway clotting. Dosing based on the rule that 1 unit/kg raises factor VIII activity ~2%.
Indications
- •Hemophilia A (bleeding + surgical coverage)
- •von Willebrand disease (vWF-containing products)
- •Acquired hemophilia
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Major bleed / surgery | Dose (units) = weight(kg) × 0.5 × desired % rise; target 80–100% for major surgery | — |
| Minor bleed | Target ~30–50% activity | — |
Pharmacokinetics
Half-life ~8–12 h → redose q8–12h or continuous infusion for surgery.
Side effects
- !Inhibitor (anti-VIII antibody) development
- !Allergic reaction
- !Thrombosis (rare)
Contraindications
- ×Known anaphylaxis to product
Clinical pearls
- ★Dose math: 1 unit/kg → ~2% activity rise. Target ~100% for major surgery.
- ★If a hemophilia A patient fails to respond, suspect an INHIBITOR → switch to bypassing agent (FEIBA/rFVIIa).
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).
- Tinzaparin
Antithrombin-mediated factor Xa > IIa inhibition; higher mean molecular weight than enoxaparin (anti-Xa:IIa ~1.9:1).
Browse all classes: /reference/drugs
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
