Reviewed on 1/19/2022

What Is Dalteparin and How Does It Work?

Dalteparin is a prescription medication used to treat Unstable Angina and Non-Q-Wave Myocardial Infarction, Deep Vein Thrombosis, and Venous Thromboembolism in people with Cancer. 

  • Dalteparin is available under the following different brand names: Fragmin 

What Are Dosages of Dalteparin?

Adult and pediatric dosage

Injectable solution, single-dose prefilled syringe

  • 2,500 IU/0.2 mL
  • 5,000 IU/0.2 mL
  • 7,500 IU/0.3 mL
  • 12,500 IU/0.5 mL
  • 15,000 IU/0.6 mL
  • 18,000 IU/0.72 mL

Injection, single-dose graduated syringe

  • 10,000 IU/mL

Injection, multiple-dose vials

  • 95,000 IU/3.8 mL (25,000 IU/mL)
    • Unstable Angina and Non-Q-Wave Myocardial Infarction 
    • Adult dosage
      • 120 IU/kg total body weight (TBW) SC every 12 hour with concurrent oral aspirin (75-165 mg per day) therapy; not to exceed 10,000 IU every 12 hours
    • Weight-based dosing:
      • Weight less than 50 kg: 5,500 IU SC every 12 hours
      • Weight 50-59 kg: 6,500 IU SC every 12 hours
      • Weight 60-69 kg: 7,500 IU SC every 12 hours
      • Weight 70-79 kg: 9,000 IU SC every 12 hours
      • Weight 80 kg or over: 10,000 IU SC every 12 hours
    • Deep Vein Thrombosis
    • Adult dosage
    • Hip replacement surgery
      • 10-14 hours before surgery: 5,000 IU SC preoperative; start the evening before surgery; allow approximately 24 hours between doses, or
      • Within 2 hours before surgery: 2,500 IU SC preoperative; start day of surgery
      • 4-8 hours after surgery: 
        • Postoperative start: 2.500 IU SC
        • Preoperative start, day of surgery: 2,500 IU SC
        • Preoperative start, evening before surgery: 5,000 IU SC
        • Allow at least 6 hours between this dose and dose to be given on postoperative Day 1
        • Adjust timing of dose on postoperative Day 1 accordingly
      • Postoperative period
        • Postoperative start: 5,000 IU SC once daily
        • Preoperative start, day of surgery: 5,000 IU SC once daily
        • Preoperative start, evening before surgery: 5,000 IU SC once daily
        • Usual duration of treatment was 5-10 days postoperatively; up to 14 days of treatment was well tolerated in clinical trials
      • Abdominal surgery
        • Patients with a risk of thromboembolic complications
        • 2,500 IU SC once daily, starting 1-2 hours prior to surgery and repeated once daily postoperatively
        • Usual duration of administration is 5-10 days
        • Patients with a high risk of thromboembolic complications (eg, malignant disorder)
        • 5,000 IU SC the evening before surgery, then once daily postoperatively 
        • Usual duration of administration is 5-10 days
        • Alternatively, in patients with malignancy, 2,500 IU SC 1-2 hours before surgery followed by 2,500 IU SC 12 hours later, and then 5,000 IU once daily postoperatively 
        • Usual duration of administration is 5-10 days
      • Patients with severely restricted mobility during acute illness
        • 5,000 IU SC once daily
        • In clinical trials, usual duration of administration was 12-14 days
    • Venous Thromboembolism in Patients with Cancer
    • Adult dosage
    • Month 1
      • Administer 200 IU/kg total body weight SC once daily; total daily dose should not exceed 18,000 IU
      • Weight 56 kg or less: 10,000 SC once daily
      • Weight 57-68 kg: 12,500 SC once daily
      • Weight 69-82 kg: 15,000 SC once daily 
      • Weight 83 kg and over: 18,000 SC once daily
    • Months 2-6
      • Administer at a dose of approximately 150 IU/kg SC once daily during months 2-6; total daily dose should not exceed 18,000 IU
      • Weight 56 kg or less: 7,500 SC once daily
      • Weight 57-68 kg: 10,000 SC once daily
      • Weight 69-82 kg: 12,500 SC once daily
      • Weight 83-98 kg: 15,000 SC once daily
      • Weight 99 kg and over: 18,000 SC once daily
    • Venous Thromboembolism
    • Pediatric dosage
      • Children younger than 4 weeks of age: Safety and efficacy not established
      • Children 4 weeks to less than 2 years of age: 150 IU/kg SC twice daily
      • Children 2 years to less than 8 years of age: 125 IU/kg SC twice daily
      • Children 8 to less than 17 years of age: 100 IU/kg SC twice daily

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."


About how much does an adult human brain weigh? See Answer

What Are Side Effects Associated with Using Dalteparin?

Common side effects of Dalteparin include:

  • low platelet levels (bruising, bleeding), and 
  • pain, bruising, or swelling at the injection site

Serious side effects of Dalteparin include:

  • hives, 
  • difficult breathing, 
  • swelling in the face or throat, 
  • back pain
  • numbness or muscle weakness in the lower body, 
  • loss of bladder or bowel control, 
  • unusual bleeding (nose, mouth, vagina, or rectum), 
  • bleeding from wounds or needle injections, 
  • continuous bleeding, 
  • easy bruising, 
  • purple or red pinpoints spots under your skin, 
  • black or bloody stools, 
  • coughing up blood
  • vomit that looks like coffee grounds, 
  • sudden weakness, 
  • severe headache, 
  • confusion, and
  • problems with speech, vision, or balance 

Rare side effects of Dalteparin include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Dalteparin?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

  • Dalteparin has severe interactions with the following drugs:
  • Dalteparin has serious interactions with at least 69 other drugs.
  • Dalteparin has moderate interactions with at least 133 other drugs.
  • Dalteparin has minor interactions with at least 17 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this drug, tell your doctor or pharmacist of all the drugs you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Dalteparin?


  • Hypersensitivity to dalteparin, heparin or pork products
  • Active major bleeding, thrombocytopenia associated with antiplatelet antibodies
  • History of heparin induced thrombocytopenia or heparin induced thrombocytopenia with thrombosis
  • Patients that have undergone epidural neuraxial anesthesia 

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Dalteparin?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Dalteparin?”


  • Risk of epidural/spinal hematoma if used in patients getting epidural/spinal anesthesia which may result in paralysis
  • Use caution in conditions with increased risk of hemorrhage, hemorrhagic diathesis, severe uncontrolled HTN, severe hepatic/renal impairment, retinopathy, thrombocytopenia, bacterial endocarditis, GI ulcer, hemorrhagic stroke, recent brain, spinal or ophthalmologic surgery
  • Periodic routine complete blood cell counts, including platelet count, blood chemistry, and stool occult blood tests are recommended during treatment
  • History of heparin-induced thrombocytopenia
  • Do not give IM
  • Can't be used interchangeably with other LMW heparins
  • Multidose vials contain benzyl alcohol as preservative (associated with potentially fatal "Gasping Syndrome" in preemies); when prescribing dalteparin multiple-dose vials in infants, consider combined daily metabolic load of benzyl alcohol from all sources including multiple-dose vials (dalteparin contains 14 mg of benzyl alcohol per mL) and other drugs containing benzyl alcohol; minimum amount of benzyl alcohol at which serious adverse reactions may occur not known
  • Therapy may enhance risk of bleeding in patients with thrombocytopenia or platelet defects; severe liver or kidney insufficiency, hypertensive or diabetic retinopathy, and recent gastrointestinal bleeding; bleeding can occur at any site during therapy; monitor thrombocytopenia of any degree closely
  • If signs or symptoms of spinal hematoma are suspected, initiate urgent diagnosis and treatment including consideration for spinal cord decompression even though such treatment may not prevent or reverse neurological sequelae
  • For patients with CrCl lower than 30 mL/min, elimination of dalteparin may be prolonged; consider doubling the timing of removal of a catheter, at least 24 hours for lower prescribed dose of dalteparin (2500 IU or 5000 IU once daily) and at least 48 hours for higher dose (200 IU/kg once daily, 120 IU/kg BID)
  • Although specific recommendation for timing of a subsequent dose after catheter removal is unknown, consider delaying this next dose for at least four hours, based on a benefit-risk assessment considering both the risk for thrombosis and the risk for bleeding in the context of the procedure and patient risk factors

Pregnancy and Lactation

  • Available data have not reported a clear association with dalteparin and adverse developmental outcomes.
  • There are risks to the mother associated with untreated VTE in pregnancy, and a potential for adverse effects on the preterm infant when used in pregnancy. 
  • Published data describe that women with a previous history of VTE in pregnancy are at higher risk for recurrence during subsequent pregnancies compared to those with no risk factor for VTE
  • Cases of “gasping syndrome” have occurred in premature infants when large amounts of benzyl alcohol have been administered (99-404 mg/kg/day)
  • Multiple-dose 3.8 mL vials of dalteparin contain 14 mg/mL of benzyl alcohol
  • Limited published data indicate that the drug is present in human milk in small amounts; no adverse effects on breastfed infant reported; there are no data on effects of drug on milk production; oral absorption of dalteparin is expected to be low, but clinical implications, if any, of this small amount of anticoagulant activity on a breastfed infant are unknown; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed child from the drug or from underlying maternal condition


Digestive Disorders: Common Misconceptions See Slideshow
Medscape. Dalteparin.


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