What Is Heparin and How Does It Work?
Heparin is a prescription drug used to prevent and treat blood clots. It may be used to prevent and treat blood clots in the lungs/legs (including in patients with atrial fibrillation). It may be used to treat certain blood clotting disorders. It may also be used to prevent blood clots after surgery, during dialysis, during blood transfusions, when collecting blood samples, or when a person is unable to move for a long time. Heparin helps to keep blood flowing smoothly by making a certain natural substance in your body (anti-clotting protein) works better. It is known as an anticoagulant.
Dosages of Heparin
Heparin lock solution
Adults
- 1 unit/mL
- 2 units/mL
- 10 units/mL
- 100 units/mL
Pediatric
- 10 units/mL
- 100 units/mL
Injectable solution
Adults
- 1,000 units/mL
- 2,500 units/mL
- 5,000 units/mL
- 10,000 units/mL
- 20,000 units/mL
Pediatric
- 1,000 units/mL
- 5,000 units/mL
- 10,000 units/mL
Premixed IV solution
Adults
- 12,500 units/250mL
- 20,000 units/500mL
- 25,000 units/250mL
- 25,000 units/500mL
Dosage Considerations – Should be Given as Follows:
Deep Vein Thrombosis and Pulmonary Embolism
Adults
- 5,000 units subcutaneously every 8-12 hours, or
- 7,500 units subcutaneously every 12 hours
Pediatric
- 100-150 units/kg intravenously once
Treatment
Adults
- 80 units/kg intravenous bolus, then continuous infusion of 18 units/kg/hour, or
- 5000 units intravenous bolus, then continuous infusion of 1300 units/hour, or
- 250 units/kg (alternatively, 17,500 units) subcutaneously, then 250 units/kg every 12 hours
Pediatric
- Infants under 1 year old: loading dose of 75 units/kg intravenously, then 28 units/kg/hour intravenously as initial maintenance dose
- Children over 1 years old: loading dose of 75 units/kg intravenously, then 20 units/kg/hour intravenously as initial maintenance dose
- Adjust heparin dose based on desired activated partial thromboplastin time (off-label)
Dosing considerations
- Numerous concentrations available; extreme caution is required to avoid medication error
Acute Coronary Syndromes
Percutaneous Coronary Intervention
- Without GPIIb/IIIa inhibitor: Initial intravenous bolus of 70-100 units/kg (target ACT 250-300 sec)
- With GPIIb/IIIa inhibitor: Initial intravenous bolus of 50-70 units/kg (target ACT over 200 sec)
STEMI
- Patient on fibrinolytics: intravenous bolus of 60 units/kg (max: 4000 units), then 12 units/kg/hour (max 1000 units/hour) as continuous intravenous infusion
- Dose should be adjusted to maintain activated partial thromboplastin time of 50-70 seconds
Unstable Angina/NSTEMI
- Initial intravenous bolus of 60-70 units/kg (max: 5000 units), then initial intravenous infusion of 12-15 units/kg/hour (max: 1000 units/hour)
- Dose should be adjusted to maintain activated partial thromboplastin time of 50-70 seconds
Dosing considerations
- Numerous concentrations available; extreme caution is required to avoid medication error
Anticoagulation
Intermittent intravenous injection
Adults
- 8,000-10,000 units intravenous initially, then 50-70 units/kg (5,000-10,000 units) every 4 to 6 hours
Pediatric
- Initially give 50-100 units/kg intravenously infusion, then 100 units/kg intravenously every 4 hours as a maintenance dose
Continuous intravenous infusion
- 5,000 units intravenous injection, followed by continuous intravenous infusion of 20,000-40,000 units/every 24 hours
Dosing considerations
- Numerous concentrations available; extreme caution is required to avoid medication error
- Heparin sodium may prolong one-stage prothrombin time; when heparin sodium is given with dicumarol or warfarin sodium, a period of at least 5 hours after last intravenous dose or 24 hours after last subcutaneous dose should elapse before blood is drawn if a valid prothrombin time is to be obtained
Catheter Patency
Adults
- Prevention of clot formation within venous and arterial catheters
- Use 100 units/mL; instill enough volume to fill lumen of catheter
Pediatric:
- Initially give 50-100 units/kg intravenous infusion, then 100 units/kg intravenous infusion every 4 hours as maintenance dose
- Infants under 10 kg: 10 units/mL; instill enough volume to fill lumen of catheter
- Children and infants over 10 kg: 10-100 units/mL; instill enough volume to fill lumen of catheter
- Dosage amount and frequency depend on catheter volume and type (off label)
- Peripheral heparin locks typically are flushed every 6-8 hours (off label)
Dosing considerations
Adults
- Numerous concentrations available; extreme caution is required to avoid medication error
- Amount and frequency depends on catheter volume and type
- Peripheral heparin locks typically are flushed every 6-8 hours
Pediatric
- Numerous concentrations available; extreme caution is required to avoid medication error
- When prescribing in infants, consider combined daily metabolic load of benzyl alcohol from all sources including heparin sodium injection (contains 9.45 mg of benzyl alcohol) and other drugs containing benzyl alcohol; the minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known
- There are no adequate, well-controlled studies on heparin use in pediatric patients; pediatric dosing recommendations are based on clinical experience
- Use preservative-free heparin in neonates and infants; benzyl alcohol preservative has been associated with serious adverse effects (gasping syndrome, which is characterized by central nervous system depression, metabolic acidosis, and gasping respirations) and death in pediatric patients
Dosing Modifications
Hepatic impairment: Caution is advised; dosage adjustment may be required
Dosing considerations
Adults- Numerous concentrations available; extreme caution is required to avoid medication error
- Amount and frequency depends on catheter volume and type
- Peripheral heparin locks typically are flushed every 6-8 hours
Pediatric
- Numerous concentrations available; extreme caution is required to avoid medication error
- When prescribing in infants, consider combined daily metabolic load of benzyl alcohol from all sources including heparin sodium injection (contains 9.45 mg of benzyl alcohol) and other drugs containing benzyl alcohol; the minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known
- There are no adequate, well-controlled studies on heparin use in pediatric patients; pediatric dosing recommendations are based on clinical experience
- Use preservative-free heparin in neonates and infants; benzyl alcohol preservative has been associated with serious adverse effects (gasping syndrome, which is characterized by central nervous system depression, metabolic acidosis, and gasping respirations) and death in pediatric patients
Dosing Modifications
- Hepatic impairment: Caution is advised; dosage adjustment may be required
What Are Side Effects Associated with Using Heparin?
Side effects associated with use of Heparin, include the following:
- heparin-induced low blood platelet count (thrombocytopenia), possibly delayed
- mild pain
- swelling of clotted blood within the tissue (hematoma)
- bleeding (hemorrhage)
- local irritation
- reddening of the skin
- injection site ulcer (after deep subcutaneous injection)
- increased liver aminotransferase
- allergic reaction (anaphylaxis)
- immune hypersensitivity reaction
- brittle and fragile bones (osteoporosis)
- asthma
- runny nose
- watery eyes
- headache
- nausea
- vomiting
Rare effects of Heparin include:
Post marketing side effects of Heparin reported include:
- heparin resistance
- gasping syndrome in infants due to benzyl alcohol preservative
- hypersensitivity
This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.
What Other Drugs Interact with Heparin?
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.
- Severe Interactions of Heparin include:
- corticorelin
- defibrotide
- mifepristone
- prothrombin complex concentrate, human
- Heparin has serious interactions with at least 68 different drugs.
- Heparin has moderate interactions with at least 141 different drugs.
- Heparin has mild interactions with at least 22 different drugs.
This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns or for more information about this medicine.
What Are Warnings and Precautions for Heparin?
Warnings
- This medication contains heparin. Do not take heparin if you are allergic to heparin or any ingredients contained in this drug.
- Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately
Contraindications
- History of heparin-induced low blood platelets (thrombocytopenia) (HIT) (with or without blood clotting abnormalities)
- Uncontrolled, active bleeding (except disseminated intravascular coagulation [DIC])
- Conditions in which coagulation tests cannot be performed at appropriate intervals
- Cases where the administration of sodium or chloride could be clinically detrimental (large volume heparin 2 unit/mL intravenous solutions only)
Effects of Drug Abuse
- No information provided
Short-Term Effects
- See "What Are Side Effects Associated with Using Heparin?"
Long-Term Effects
- See "What Are Side Effects Associated with Using Heparin?"
Cautions
- Any risk factor for hemorrhage such as bacterial infection within the heart (subacute bacterial endocarditis), blood disease, abnormally heavy and long periods (menorrhagia), dissecting aneurysm, major surgery, spinal anesthesia, blood clotting disorder (hemophilia), gastrointestinal (GI) ulcerative lesions, liver disease, and impaired blood flow (hemostasis)
- Heparin-induced thrombocytopenia may occur (with or without thrombosis) including thrombus formation on a prosthetic cardiac valve; immune-mediated reaction resulting from irreversible aggregation of platelets; monitor thrombocytopenia of any degree; if platelet count falls below 100,000/m³, discontinue anticoagulants
- Monitor therapy with activated partial thromboplastin time (aPTT)
- Heparin may prolong the time for your blood to clot (PT)
- Potential medication errors: Do not use heparin sodium injection as a catheter lock-flush product; heparin sodium injection is supplied in vials containing various strengths of heparin; these include vials containing a highly concentrated solution of 10,000 units in 1 mL, which have been mistaken for 1 mL low-concentration catheter lock-flush vials
- Geriatric dosing: Lower doses may be necessary; patients over 60 years may have enhanced serum levels and response compared with patients under 60 years receiving similar dosages
- Heparin sodium may prolong one-stage prothrombin time; when heparin sodium is given with dicumarol or warfarin sodium, a period of at least 5 hours after last intravenous dose or 24 hours after last subcutaneous dose should elapse before blood is drawn if a valid prothrombin time is to be obtained
- If preserved with benzyl alcohol, do not administer to neonates, infants, pregnant women, or breastfeeding women; benzyl alcohol has been associated with serious adverse events and death, particularly in pediatric patients (gasping syndrome)
- Blood coagulation tests guide therapy for full-dose heparin; monitor platelet count and hematocrit in all patients receiving heparin
- Heparin resistance may be observed in patients with antithrombin deficiency, increased heparin clearance, elevations of heparin binding proteins, elevations of in factor VIII and/or fibrinogen and may require doses greater than 35,000 units/24hr to maintain therapeutic aPTT; frequently encountered in patients with fever, thrombosis, infections with thrombosing tendencies, thrombophlebitis, cancer, myocardial infarction, and postsurgical patients; may benefit from measurements of anticoagulant effects using anti-factor plasma (Xa) levels
- May suppress aldosterone production and cause elevated potassium level
- Use with caution in patients with documented hypersensitivity to heparin; use only in life-threatening situations when use of alternate anticoagulant is not possible
- Osteoporosis may occur with prolonged (greater than 6 months) use due to a reduction in mineral bone density
- Some preparations may contain sulfite, which may cause allergic reactions
Pregnancy and Lactation
- Use heparin during pregnancy with caution if benefits outweigh risks. Animal studies show risk and human studies are not available, or neither animal nor human studies were done
- Heparin is not excreted in breast milk, therefore it is safe to use when breastfeeding
From
Medscape. Heparin.
https://reference.medscape.com/drug/calciparine-monoparin-heparin-342169#0
RxList. Heparin. Side Effects Center.
https://cnes.jsintl.com.cn/?blood=heparin-drug.htm