Cardiology Research and Practice

Review Article

Saddle Pulmonary Embolism in a Cancer Patient with Thrombocytopenia: A Treatment Dilemma

Table 2

Pharmacokinetics of different anticoagulants [22–29].


Anticoagulant	Molecular weight	(h)	Elimination route	Antidote	Platelet monitoring	AntiXa monitoring

Enoxaparin (lovenox)	3,500–5,500	4.5–7	Renal		- Thrombocytopenia of any degree should be monitored closely - Discontinue for platelet count falls below 100,000/mm³	- 1 mg/kg Q12 = 0.6–1.1 IU/mL - 1.5 mg/kg daily = 1.0–1.5 IU/mL
Dalteparin (fragmin)	5,600–6,400	3–5	Renal	Protamine sulfate 1 mg per 100 U of heparin or less than 100 mg over 2 hours to lower risk of reaction. Protamine partially reverses the effect of LMWH	- For platelet counts between 50,000 and 100,000/mm³, reduce dose of dalteparin by 2,500 IU until the platelet count recovers to ≥100,000/mm³ - Discontinue for platelet counts <50,000/mm³	- 100 IU/kg Q12 = 0.4–1.1 IU/mL - 200 IU/kg daily = 1.0-2.0 IU/mL
Tinzaparin (innohep)	5,600–7,500	3-4	Renal		- Thrombocytopenia of any degree should be monitored - Discontinue for platelet count below 100,000/mm³	175 IU/kg = 0.85–1.0 IU/mL
Unfractionated heparin	5,000–30,000	1-2	Renal/endothelial	Protamine sulfate 1 mg per 100 U of heparin or less than 100 mg over 2 hours to lower risk of reaction.	- Thrombocytopenia of any degree should be monitored - Discontinue for platelet count below 100,000/mm³ or if recurrent thrombosis develops (sign and symptoms of HIT)	aPTT monitoring
Fondaparinux (arixtra)	<2,500	17–21	Renal	Recombinant factor VIIa 90 mcg/kg	- Thrombocytopenia of any degree should be monitored - Discontinue for platelet count falls below 100,000/mm³	- 2.5 mg = peak at steady state 0.39–0.5 mg/L; trough at steady state 0.14–0.19 mg/L - 5 mg, 7.5 mg, 10 mg = peak at steady state 1.20–1.26 mg/L; trough at steady state 0.46–0.62 mg/L

IV: intravenous; SC: subcutaneous; U: unit; UFH: unfractionated heparin; LMWH: low-molecular-weight heparin; : half-life elimination; HIT: heparin-induced thrombocytopenia; aPTT: activated partial thromboplastin time.