Tinzaparin
Innohep
Low-molecular-weight heparin (LMWH)
Antithrombin-mediated factor Xa > IIa inhibition; higher mean molecular weight than enoxaparin (anti-Xa:IIa ~1.9:1).
Indications
- •VTE treatment + prophylaxis
- •Cancer-associated VTE
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Treatment | 175 units/kg SC daily | — |
| Prophylaxis | 4500 units SC daily | — |
Pharmacokinetics
Half-life ~3–4 h. Less renal dependence than enoxaparin — may be preferred in mild-moderate renal impairment.
Side effects
- !Bleeding
- !HIT (uncommon)
Contraindications
- ×Active bleeding
- ×HIT history (relative)
Reversal / antidote
Protamine partial reversal
Clinical pearls
- ★ASRA neuraxial: standard LMWH timing (12 h prophylactic / 24 h therapeutic).
- ★Larger molecule → less renal accumulation than enoxaparin.
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).
- Fondaparinux
Binds antithrombin → selective, exclusive factor Xa inhibition (no IIa activity). Does NOT cause HIT — safe alternative in HIT patients.
Browse all classes: /reference/drugs
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
- •ASRA regional anesthesia in the anticoagulated patient guidelines, 2018
