Heparin

Drug Overview

Heparin is an anticoagulant primarily used for the prevention and treatment of thrombotic diseases. This medication inhibits the blood coagulation process, preventing the expansion of existing thrombi or the formation of new clots, commonly used in emergency and hospitalized patients.

Heparin is usually administered via injection, including subcutaneous injection or intravenous infusion, suitable for acute thrombus management. Its effects are rapid but short-lived, often combined with other anticoagulants for long-term use.

Brand Names and Generic Name

Brand names include Hepflush® and Hirudin®, with the generic name being Heparin Sodium. Different formulations may have different brand names; it is important to verify the medication components and indications before use.

Drug Classification

Heparin is classified as an anticoagulant of the heparin class, belonging to anticoagulants that are not direct thrombin inhibitors. This class primarily acts on Factor Xa and Factor IIa, blocking the coagulation cascade.

Indications

1. Acute treatment of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)
2. Prevention of thrombotic complications in myocardial infarction patients
3. Anticoagulation during extracorporeal circulation in hemodialysis
4. Prevention of thrombosis in long-term bedridden patients

Specific uses include postoperative thromboprophylaxis and coagulation abnormalities caused by certain blood disorders. Physicians will adjust dosage based on patient weight and coagulation parameters.

Common Side Effects

Mild side effects:

• Bruising or swelling at the injection site
• Dizziness or mild headache
• Loss of appetite or diarrhea

Serious side effects: Seek immediate medical attention

• Unexplained persistent bleeding (e.g., hematuria, melena)
• Widespread skin ecchymosis or purpura
• Abnormal bleeding at the injection site

Warnings and Precautions

Contraindications:

• Active bleeding disorders (e.g., gastrointestinal bleeding, intracranial hemorrhage)
• Severe hepatic or renal impairment
• Allergy to heparin or porcine mucosal components

Pregnancy category C, used only when necessary. Long-term use may lead to decreased bone density; regular monitoring of platelet count and coagulation time is required. During treatment, invasive procedures should be avoided.

Drug Interactions

Concurrent use with oral anticoagulants (e.g., warfarin) increases bleeding risk; INR monitoring is essential. Use with non-steroidal anti-inflammatory drugs (NSAIDs) may cause gastrointestinal bleeding.

When combined with platelet inhibitors (e.g., aspirin) or local anesthetics, dosage adjustments are necessary. Injectable heparin should not be mixed with certain antibiotics (e.g., aminoglycosides).

Dosage and Administration

Dosage is adjusted based on body weight and treatment goals, generally administered subcutaneously every 8-12 hours. Severe cases may require continuous intravenous infusion, which must be performed by healthcare professionals.

During therapy, regular measurement of activated partial thromboplastin time (aPTT) and anti-Xa activity is necessary to ensure efficacy and safety. Self-adjustment of dosage may lead to bleeding or inadequate therapeutic effect.

Missed Dose Management

If a subcutaneous injection is missed, it should be administered immediately, maintaining at least a 4-hour interval from the next dose. If more than 3 hours have passed since the scheduled time, contact healthcare personnel for re-evaluation of the treatment plan.

Overdose Management

Overdose may cause internal bleeding; immediate discontinuation of medication and administration of prothrombin complex concentrate or protamine sulfate as an antidote are recommended.

Severe bleeding requires hospitalization for observation, and may necessitate blood transfusion or surgical hemostasis. Patients should carry a medical alert bracelet indicating anticoagulant use.

Frequently Asked Questions

When administering subcutaneous heparin, how should injection sites be selected to reduce skin damage?

It is recommended to rotate injections among areas with thicker subcutaneous fat such as the abdomen, flank, or outer thigh. The skin should be cleaned before injection, disinfected with 75% alcohol, and injections should be at a 45 to 90-degree angle to reduce the risk of hematoma or tissue necrosis.

What should be done if bleeding occurs from the gums or urine during heparin therapy?

This may be a bleeding side effect; stop the medication immediately and seek medical evaluation. Avoid using antiplatelet drugs (e.g., aspirin) or NSAIDs, and reduce strenuous activity to prevent worsening bleeding. The physician may adjust the dose or switch to another anticoagulant.

What monitoring parameters are important when combining heparin with oral anticoagulants (e.g., warfarin)?

Regular INR monitoring is necessary during combined therapy to ensure safe transition from heparin bridging to warfarin. Typically, heparin is gradually discontinued once INR reaches the therapeutic range, but care must be taken to avoid excessive INR and bleeding risk. The combined use usually does not exceed 5 days, following the physician’s instructions.

What dietary restrictions should patients on heparin observe?

Avoid foods high in vitamin K (e.g., spinach, broccoli) as they may affect anticoagulation. Also, avoid herbal supplements like ginseng and ginkgo that have antiplatelet effects. Alcohol intake should be minimized, as alcohol can increase bleeding risk.

How should missed doses of heparin be handled to maintain efficacy?

If a dose is missed, it should be administered as soon as possible. If less than 6 hours remain before the next scheduled dose, skip the missed dose and continue with the regular schedule. Do not double doses to compensate. Frequent missed doses should be discussed with a healthcare provider to consider adjustments in administration method or dosing interval.