Dalteparin Sodium

Dalteparin, a low molecular weight heparin (LMWH) prepared by nitrous acid degradation of unfractionated heparin of porcine intestinal mucosa origin, is an anticoagulant. It is composed of strongly acidic sulphated polysaccharide chains with an average molecular weight of 5000 and about 90% of the material within the range of 2000-9000. LMWHs have a more predictable response, a greater bioavailability, and a longer anti-Xa half life than unfractionated heparin. Dalteparin can also be safely used in most pregnant women. Low molecular weight heparins are less effective at inactivating factor IIa due to their shorter length compared to unfractionated heparin.

Dalteparin is a low molecular weight heparin used for the prophylaxis of thrombotic events in certain patients and prevent acute cardiac ischemic events in patients with unstable angina and non-Q-wave myocardial infarction.

Dalteparin is used as a prophylaxis for deep-vein thrombosis and pulmonary embolisms in patients undergoing general surgery (e.g., abdominal, gynecologic, urologic), and in patients with acute medical conditions (e.g. cancer, bed rest, heart failure, severe lung disease). It is also used in patients who have severely restricted mobility, which poses a risk for thromboembolic complications.

Dalteparin is also used concomitantly with aspirin and/or other therapy (e.g., nitrates, β-adrenergic blockers, clopidogrel, platelet glycoprotein [GP] IIb/IIIa-receptor inhibitors) to reduce the risk of acute cardiac ischemic events. The patients who undergo this treatment combination have unstable angina or non-ST-segment elevation/non-Q-wave myocardial infarction (i.e., non-ST-segment elevation acute coronary syndromes).

It is also used in the prevention of clotting during hemodialysis and hemofiltration in connection with acute renal failure or chronic renal insufficiency.

• Cardiovascular Events
• Clotting
• Deep Vein Thrombosis
• Symptomatic Venous Thromboembolism
• Venous Thromboembolism

Dalteparin has an antithrombin binding site that is essential for high affinity binding to the plasma protein antithrombin (ATIII). Anti-Xa activity of plasma is used as both as an estimate of clotting activity, and as a basis to determine dosage. Its use should be avoided in patients with a creatinine clearance less than 20mL/min. In these patients, unfractionated heparin should only be used. As for monitoring, active partial thromboplastin time (aPTT) will only increase at high doses of low molecular weight heparins (LMWH). Therefore, monitoring aPTT is not recommended. However, anti-Xa activity can be measured to monitor the efficacy of the LMWH.

Dalteparin potentiates the activity of ATIII, inhibiting the formation of both factor Xa and thrombin. The main difference between dalteparin and unfractionated heparin (UH) is that dalteparin preferentially inactivates factor Xa. As a result, only a slight increase in clotting time [(i.e. activated partial thomboplastin time (APTT)] is observed relative to UH. For this same reason, APTT is not used to monitor the effects of dalteparin except as an indicator for overdosage.

Almost completely absorbed after subcutaneous (sc) doses, with a bioavialability of about 87%.

3 litres

Less than unfractionated heparin, which is more than 90%.

After 4 hours, about 20% is seen in urine. Most of the remainder is found in the liver, gastrointestinal tract and kidney. The kidneys are the major site of dalteparin excretion (approximately 70% based on animal studies).

Terminal Half life: Intravenous - 2 hours. Subcutaneous - 3-5hours

Excreted via kidneys. The plasma clearance rate is 33 mL/min.

Overdosage: hemorrhagic complications. Adverse Drug Reaction: (common) osteopenia with extended use; mild, reversible non-immunological thrombocytopenia; transient elevation of liver transaminases; alopecia. (uncommon): severe immunologically-mediated heparin-induced thrombocytopenia; anaphylactic reactions; skin rash, skin necrosis; retroperitoneal hemorrhage; angioedema

• Avoid herbs and supplements with anticoagulant/antiplatelet activity. Examples include garlic, ginger, bilberry, danshen, piracetam, and ginkgo biloba.

• Prophylaxis of clotting in extracorporeal circulation in haemodialysis or haemofiltration: 30-40 U/kg IV inj, then 10-15 U/kg/hr as IV infusion.

• Venous thromboembolism: 200 U/kg/day as a single or in 2 divided doses in pregnant and high-risk patients. Max: 18,000 U/day.
• Prophylaxis of venous thromboembolism during surgical procedures Moderate risk: 2,500 U given 1-2 hr pre-op then 2,500 U once daily for 5-7 days or until the patient is fully ambulant. High risk: 2,500 U given 1-2 hr before and 8-12 hr after the procedure then 5,000 U daily.
• Unstable angina: 120 U/kg 12 hrly continued for 5-8 days w/ low-dose aspirin. Max: 10,000 U 12 hrly.