How does Fragmin work?

Fragmin works by stopping the factors that clot our blood from forming, which prevents clots that could otherwise lead to a stroke or heart attack.

What drugs should not be taken with Fragmin?

Fragmin can interact with other medications that affect bleeding, such as aspirin, NSAIDs, other medications used to stop clots (e.g., warfarin, clopidogrel), or any other low molecular weight heparin. Please consult your healthcare provider before taking these medications to prevent bleeding issues.

How long does it take for Fragmin to work?

Fragmin may take as long as four hours to reach peak levels after administration. However, if given in the hospital setting through a vein, it may act more quickly due to faster absorption.

How do I stop taking Fragmin?

Do not stop taking Fragmin without first consulting your healthcare provider.

Should I stop my other medications while taking Fragmin?

Do not stop taking your other medications unless directed by your healthcare provider first.

Fragmin (Dalteparin) - Subcutaneous: Uses, Side Effects, Dosages

Warning:

Spinal or epidural anesthesia should be monitored if you are taking this medication or any other common surgical medications, such as low molecular weight heparin (LMWH) or heparinoids. Any spinal anesthesia or puncture could rarely cause a pool of blood or a spinal epidural hematoma to occur, but the administration of Fragmin along with this procedure could increase the risk. Other factors that could increase the risk of a spinal hematoma include the use of a spinal epidural catheter, combined use of other drugs that could affect bleeding (e.g., non-steroidal anti-inflammatory drugs [NSAIDs], platelet inhibitors, and other blood thinners), a history of trauma or repeated epidural or spinal punctures, and a history of a spinal deformity or surgery.

Some time may need to pass between the administration of Fragmin and an injection to the spinal area. Seek medical help immediately if you have any signs of nerve problems like back pain, numbness or tingling, muscle weakness, paralysis, or loss of bladder or bowel control.

…

What Is Fragmin?

Fragmin (dalteparin) is a prescription medication used as a subcutaneous (under the skin) injection to prevent certain blood clots. It is also used along with aspirin to prevent complications from chest pain and heart attacks.

Fragmin is commonly known as low molecular weight heparin (LMWH). It is also referred to as a blood thinner or anticoagulant and can directly stop the factors in the blood that form clots after traumatic injuries or during surgery.

Drug Facts

Generic Name: Dalteparin

Brand Name(s): Fragmin

Drug Availability: Prescription only

Administration Route: Subcutaneously

Therapeutic Classification: Anticoagulant

Available Generically: No

Controlled Substance: No

Active Ingredient: Low molecular weight heparin (dalteparin)

Dosage Form(s): Injection

What Is Fragmin Used For?

The Food and Drug Administration (FDA) approved Fragmin to prevent blood clotting or coagulation during surgery and to treat blood clots in various conditions.

This medication is indicated to:

Treat venous thromboembolism (VTE) in those with cancer to reduce recurrence
Prevent deep vein thrombosis (DVT) in abdominal surgery, hip replacement surgery, or in patients with severely restricted mobility during an illness
Prevent complications of unstable chest pain or angina, such as heart attack or stroke, when combined with aspirin
Treat VTE in children 1 month and older to reduce recurrence

How to Take Fragmin

Take Fragmin as instructed by your healthcare provider.

You'll administer Fragmin with a clean or sterile injection underneath the skin's surface, on the right or left side of the stomach, thigh, or buttocks. Keep the following in mind when giving yourself the injection:

Wash your hands before and after use.
Before giving the shot, inspect the drug, as it is not recommended to use it when the solution is cloudy, leaking, has particles, or changes color.
Move the injection site of each dose to reduce bruises.
It is best to be seated or lying down when administering it.
Throw away needles in a needle/sharp disposal box or a sturdy container, like a milk bottle. It is important not to reuse or share needles.

Storage

Store Fragmin in a dry area at all times to protect from moisture. Store it at room temperature (between 68 F and 77 F). Do not keep it in the bathroom. For the multidose vials, you can store them at room temperature for up to two weeks after the first penetration of the rubber stopper. After two weeks, discard the medication.

This medication should not be left in the car or the refrigerator. Keep it in an area specified by your healthcare provider or as directed on the medication label. Ensure the medication is out of reach of children and pets.

Off-Label Uses

Fragmin can be used as a non-FDA-approved medication for those who have more severe cases of clots, such as DVT, VTE, or even a pulmonary embolism (PE). It is not uncommon for it to be prescribed off-label to:

Treat deep vein clots like in the legs, thigh, or pelvis
Treat and prevent lung clots
Mechanical heart valve (valvular disease)
Superficial vein clots, acute and symptomatic
Prevent clots in non-surgical conditions, pregnancy, and knee surgery
Treat clots in pregnant people

How Long Does Fragmin Take to Work?

Fragmin reaches peak levels in the body about four hours after administration.

What Are the Side Effects of Fragmin?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

This medication, like many others, comes with side effects. Possible side effects may be mild, serious, or long-term.

Common Side Effects

The most common side effects of Fragmin are pain, bleeding, and bruising at the injection site. Lab tests may also reveal elevated liver transaminase levels, but this should be temporary.

If these symptoms become more bothersome over time, consult your healthcare provider before continuing.

Severe Side Effects

Call your healthcare provider immediately if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you have a medical emergency. Serious side effects and their symptoms can include the following:

Purple or reddish discoloration around the injection site
Moderate-to-severe pain and bruising at the injection site
Easy bruising or bruises without any cause
Unusual bleeding (vaginal, abdominal, rectal, nose, mouth, or gums)
Bleeding that won't stop
Signs of an allergic reaction such as rash, hives, tightness in the chest or throat, or swelling of the mouth, face, lips, tongue, or throat
Signs of severe bleeding such as coughing up blood or vomit that appears the color of coffee grounds; blood in the urine; black, red, or tarry stools; or uncontrollable bleeding
Hemorrhagic stroke (bleeding inside the brain) can cause weakness or numbness in part of the face, difficulty speaking, or difficulty walking.

Long-Term Side Effects

In many thoroughly compared studies, low molecular weight heparins, such as Fragmin, increased the risk of fractures and bone mineral disease (BMD) in those who used the medication for up to 24 months.

It is a good idea to speak with your healthcare provider about receiving a bone test before starting Fragmin, especially if you are over 65, have a history of brittle or broken bones and have a bone disease such as osteoporosis.

Report Side Effects

Fragmin may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

(800) 332-1088

Dosage: How Much Fragmin Should I Take?

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For injection dosage form (solution):
- For prevention of blood clots after unstable angina (chest pain) or non–Q-wave myocardial infarction (a type of heart attack):
  - Adults—Dose is based on body weight and must be determined by your doctor. The dose is usually 120 international units (IU) per kilogram (kg) of body weight injected under the skin (but not more than 10,000 IU) given every 12 hours for 5 to 8 days. Unless your doctor recommends otherwise, aspirin should be given 75 to 165 milligrams (mg) once a day.
  - Children—Use and dose must be determined by your doctor.
- For prevention of deep venous thrombosis after abdominal surgery:
  - Adults—2,500 or 5,000 international units (IU) injected under the skin once a day, or 2,500 IU injected under the skin followed by 2,500 IU injected under the skin given 12 hours later and then 5,000 IU injected under the skin once a day for 5 to 10 days.
  - Children—Use and dose must be determined by your doctor.
- For prevention of deep venous thrombosis after hip replacement surgery:
  - Adults—
    - If started the evening before surgery: 5,000 international units (IU) injected under the skin 10 to 14 hours before surgery followed by 5,000 IU injected under the skin 4 to 8 hours after surgery, then 5,000 IU injected under the skin once a day.
    - If started on the day of surgery: 2,500 IU injected under the skin within 2 hours before surgery followed by 2,500 IU injected under the skin 4 to 8 hours after surgery, then 5,000 IU injected under the skin once a day.
    - If started after surgery: 2,500 IU injected under the skin given 4 to 8 hours after surgery, then 5,000 IU injected under the skin once a day, given 5 to 10 days after surgery.
  - Children—Use and dose must be determined by your doctor.
- For prevention of deep venous thrombosis in medical patients with acute illness:
  - Adults—5,000 international units (IU) injected under the skin once a day for 12 to 14 days.
  - Children—Use and dose must be determined by your doctor.
- For symptomatic deep venous thrombosis and pulmonary embolism in children:
  - Children 8 to 16 years of age—Dose is based on body weight and must be determined by your doctor. At first, 100 internation units (IU) per kilogram (kg) of body weight injected under the skin 2 times a day. Your doctor will adjust your dose as needed.
  - Children 2 to 7 years of age—Dose is based on body weight and must be determined by your doctor. At first, 125 IU per kg of body weight injected under the skin 2 times a day. Your doctor will adjust your dose as needed.
  - Children 4 weeks to 1 year of age—Dose is based on body weight and must be determined by your doctor. At first, 100 IU per kg of body weight injected under the skin 2 times a day. Your doctor will adjust your dose as needed.
  - Children younger than 4 weeks of age—Use and dose must be determined by your doctor.
- For symptomatic deep venous thrombosis and pulmonary embolism in patients with cancer:
  - Adults—Dose is based on body weight and must be determined by your doctor. On the first 30 days, 200 international units (IU) per kilogram (kg) of total body weight injected under the skin (but not more than 18,000 IU) once a day. On months 2 to 6, 150 IU per kg of body weight injected under the skin once a day.
  - Children—Use and dose must be determined by your doctor.

Modifications

Certain factors may affect how you take your medication. The following should be kept in mind when taking Fragmin:

Children: Fragmin can be safely used in children aged 1 month or older to treat symptomatic clots.
Pregnancy: People who are pregnant or who are trying to become pregnant should speak with their primary healthcare provider before receiving Fragmin. It is not fully understood whether it has long-term effects on the fetus during pregnancy. Common alcohol used as a preservative in multidose vials may cross the placenta and affect the fetus. Fragmin's use while pregnant should be weighed with the potential adverse outcomes associated with untreated VTE.
Advanced age: No specific adjustments are needed for those 65 or older compared with the younger population, as this medication has been proven safe in the most recent information available.
Underweight older adults with poor kidney function: You may be at increased risk of issues with this medication if you have poor kidney function, are over the age of 65, and weigh less than 100 pounds (lbs). Your healthcare provider should adjust the dose appropriately if you have poor kidney function and are underweight.

Missed Dose

If you miss a dose, take it as soon as you remember. However, if it is closer to the time for your next dose than the missed one, skip the missed dose and go back to your regular dosing schedule.

Do not take two doses of Fragmin at the same time, as it increases the bleeding risk.

Overdose: What Happens If I Take Too Much Fragmin?

Taking too much Fragmin can cause heavy bleeding. In the case of an overdose, contact a healthcare provider or get emergency medical help as soon as possible. You can also contact a regional Poison Control Center if other options are unavailable.

Do not risk delaying the issue even if no symptoms are present. If you or a loved one has taken too many injections of Fragmin in a day, contact help as soon as possible.

What Happens If I Overdose on Fragmin?

If you think you or someone else may have overdosed on Fragmin, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Fragmin, call 911 immediately.

911

Precautions

It is very important that your doctor check your or your child's progress at regular visits to make sure that the medicine is working properly. Blood tests may be needed to check for unwanted effects. Be sure to keep all appointments.

This medicine may increase your risk of bleeding or bruising. This risk is higher if you have poorly controlled high blood pressure, a heart infection, stomach ulcers, or other bleeding problems. Check with your doctor right away if you notice any unusual bleeding or bruising, black, tarry stools, blood in the urine or stools, or pinpoint red spots on your skin. Avoid picking your nose. If you need to blow your nose, blow it gently.

This medicine may increase your risk of serious bleeding or nerve problems in your spine. This risk is higher if you have a catheter in your back for pain medicine or anesthetics, or have an injection into your spine (sometimes called an "epidural" or "spinal"). Other factors include traumatic or repeated epidural or spinal punctures in the past, spinal deformity, previous spinal surgery, or use of other medications that increase the risk of bleeding. Check with your doctor right away if you develop weakness or numbness in your legs or feet, or loss of urine or bowel control.

Call your doctor right away if you start having pains in the chest, groin, or legs, especially the calves, difficulty with breathing, severe, sudden headache, slurred speech, sudden, sudden loss of coordination, sudden, severe weakness or numbness in the arm or leg, or vision changes. These may be symptoms of thromboembolism.

Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.

Be careful not to cut yourself when you are using sharp objects, such as a safety razor or fingernail or toenail cutters. Avoid contact sports or other situations where bruising or injury could occur.

This medicine contains benzyl alcohol which may cause serious unwanted effects to newborn or premature infants. Talk to your doctor if you have concerns about this.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before having surgery or medical tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Fragmin?

Before starting Fragmin or any other LMWH, speak with your healthcare provider if you have or have a history of the following:

Allergies to Fragmin or any other medication of the LMWH family
Bleeding from the stomach
Bleeding from the brain
Severe clotting issues
A decreased amount of platelets (thrombocytopenia)
Bacterial infection in the heart
High blood pressure
Diabetic retinopathy, a complication of diabetes affecting the eyes

What Other Medications Interact With Fragmin?

Fragmin should be carefully administered when taking certain medications. Do not take the following medications with Fragmin, as they may intensify Fragmin's effects on the body:

Aspirin
Drugs that reduce clotting, such as Jantoven (warfarin) or nonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil or Motrin (ibuprofen), Naprosyn (naproxen) or Celebrex (celecoxib)
Antiplatelet medications or other medications used for preventing blood clots from forming in the arteries, such as Plavix (clopidogrel)

This is not a complete list of medicines that interact with Fragmin. Talk with your pharmacist or healthcare provider for more detailed information about potential medication interactions. Furthermore, tell your healthcare provider about any other medicines you take or plan to take, including over-the-counter (OTC), nonprescription products, vitamins, herbs, or plant-based medicines.

What Medications Are Similar?

Other drugs in the same family of low molecular weight heparins are:

Lovenox (enoxaparin)
Innohep (tinzaparin)

Frequently Asked Questions

What is Fragmin used for?

Fragmin helps prevent or treat the formation of clots in the blood. It can also be used with aspirin to prevent complications from chest pain and heart attacks.
How does Fragmin work?

Fragmin works by stopping the factors that clot our blood from forming, which prevents clots that could otherwise lead to a stroke or heart attack.
What drugs should not be taken with Fragmin?

Fragmin can interact with other medications that affect bleeding, such as aspirin, NSAIDs, other medications used to stop clots (e.g., warfarin, clopidogrel), or any other low molecular weight heparin. Please consult your healthcare provider before taking these medications to prevent bleeding issues.
How long does it take for Fragmin to work?

Fragmin may take as long as four hours to reach peak levels after administration. However, if given in the hospital setting through a vein, it may act more quickly due to faster absorption.
What are the side effects of Fragmin?
Side effects to expect when taking Fragmin include:
- Irritation from the site of injection
- Pain from the area of the injection site
- Bruising
- Bleeding
- Elevated liver transaminase levels
How do I stop taking Fragmin?

Do not stop taking Fragmin without first consulting your healthcare provider.
Should I stop my other medications while taking Fragmin?

Do not stop taking your other medications unless directed by your healthcare provider first.

How Can I Stay Healthy While Taking Fragmin?

Taking care of yourself and your overall health is important no matter what, especially so while you are dealing with a health condition.

It is always best to maintain a healthy diet and exercise when you can. Even incorporating a short walk into each day and working your way up to more physical activity can be beneficial. Check with your healthcare provider before beginning an exercise program to ensure your level of exercise is appropriate for you.

Continue taking your medication as prescribed; follow your healthcare provider's instructions closely if you are giving yourself the injection. Remember to follow up with your healthcare team regularly if you have any questions or concerns about your therapy.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

The author would like to recognize and thank Jaycob Mathew Peña for contributing to this article.

9 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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Prescribers' Digital Reference. Dalteparin sodium - drug summary.
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Villani M, Ageno W, Grandone E, Dentali F. The prevention and treatment of venous thromboembolism in pregnancy. Expert Rev Cardiovasc Ther. 2017;15(5):397-402. doi:10.1080/14779072.2017.1319279
Gajic-Veljanoski O, Phua CW, Shah PS, Cheung AM. Effects of long-term low-molecular-weight heparin on fractures and bone density in non-pregnant adults: a systematic review with meta-analysis. J Gen Intern Med. 2016;31(8):947-957. doi:10.1007/s11606-016-3603-8

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