Dalteparin !
A low-molecular-weight heparin injected under the skin to prevent and treat venous clots, including clots linked to cancer.
Updated 2026-11-01
The figure shows antithrombin bound to the heparin pentasaccharide, the five-sugar sequence through which dalteparin binds and activates it (not a dalteparin chain).
Mechanism of action
Dalteparin is a low-molecular-weight heparin. Like heparin, it binds antithrombin through a five-sugar sequence and speeds up its inhibition of clotting factors. Its chains are mostly too short to bridge antithrombin to thrombin, so it acts mainly on factor Xa. Its anticoagulant response is predictable enough that routine monitoring is not needed.
- Dalteparin binds antithrombin through its pentasaccharide
- Antithrombin blocks factor Xa much faster
- Less thrombin forms; little direct effect on thrombin
Pharmacokinetics
- Absorption
- Given under the skin, once or twice a day.
- Elimination
- Through the kidneys; kidney impairment prolongs its action, and anti-Xa levels may be needed.
Indications
- Prevention of deep vein thrombosis after surgery or in people on bed rest. Deep vein thrombosis →
- Treatment and secondary prevention of venous thromboembolism in people with cancer. Pulmonary embolism →
- Angina and heart attacks, together with aspirin, to prevent serious complications. Myocardial Infarction (Heart Attack) →
Adverse effects
Common
- Nosebleeds
- Redness, pain, bruising or sores at the injection site
- Dizziness
Contraindications
- Active major bleeding that cannot be stopped
- History of heparin-induced thrombocytopenia
- Allergy to dalteparin, heparin or pork products
Key interactions
- Aspirin, NSAIDs, antiplatelets and other anticoagulants
- Raise the risk of bleeding.
- Neuraxial anaesthesia or epidural catheters
- Risk of spinal haematoma.
What is monitored
- Platelet count and haemoglobin
- Kidney function; anti-Xa levels in kidney impairment, obesity, pregnancy or children
- Neurological checks after spinal or epidural procedures
Administration and safety
- Subcutaneous injection; vials and prefilled syringes come in several strengths, so the label is checked against the order
- Prescribed in international units, not milligrams like enoxaparin: the two are not interchangeable
- Injection sites are rotated; the patient or carer is taught self-injection when it continues at home
Nursing care
- Ask about previous heparin-induced thrombocytopenia and pork allergy before the first dose
- Check baseline platelets, haemoglobin and kidney function
- Watch for bleeding and for falling platelets during treatment
- After spinal or epidural procedures, check for back pain, numbness or leg weakness
Pregnancy and breastfeeding
Low-molecular-weight heparins can be used in pregnancy; anti-Xa levels may be checked because needs change.
Test yourself
Think of the answer, then tap the question to see it.
How is the dose of dalteparin expressed, compared with enoxaparin?
Dalteparin is prescribed in international units; enoxaparin in milligrams. They are not interchangeable.
In which group of patients is dalteparin a classic choice for long treatment of venous clots?
People with cancer-associated venous thromboembolism.
When may anti-Xa levels be needed with a low-molecular-weight heparin such as dalteparin?
In kidney impairment, obesity, pregnancy and children, where its effect is less predictable.
Related drugs
Related conditions
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Dalteparin Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2019); eEML - Electronic Essential Medicines List (World Health Organization, 2025); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 36 (McGraw Hill, 2023).
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Representative model, for educational purposes only.