Usage
Bemiparin, a low molecular weight heparin (LMWH), is an anticoagulant prescribed for:
- Treatment of deep vein thrombosis (DVT) with or without pulmonary embolism (PE).
- Prevention of venous thromboembolism (VTE) in surgical (general, orthopedic) and non-surgical patients.
- Preventing clot formation in extracorporeal circuits during hemodialysis.
It is classified as an anticoagulant.
Alternate Names
Bemiparin sodium is the generic name. Brand names include Zibor, Hibor, Ivor, Badyket, and others.
How It Works
Pharmacodynamics:
Bemiparin primarily acts by accelerating the activity of antithrombin III. This inhibits Factor Xa and, to a lesser degree, Factor IIa (thrombin), ultimately reducing fibrin clot formation and preventing thrombus development or extension. It exhibits a higher ratio of anti-Xa to anti-IIa activity compared to unfractionated heparin.
Pharmacokinetics:
- Absorption: Rapidly absorbed after subcutaneous injection (bioavailability ≈ 96%). Peak anti-Xa activity reached in 2-4 hours.
- Metabolism and Excretion: Primarily eliminated via renal and hepatic routes. Elimination is prolonged in patients with renal or hepatic impairment.
- Half-life: 5-6 hours (therapeutic dosing).
Mode of Action:
Bemiparin binds to antithrombin III, causing a conformational change that enhances its ability to inactivate Factor Xa. The complex of bemiparin-antithrombin III inhibits Factor Xa, reducing the conversion of prothrombin to thrombin. This ultimately decreases fibrin formation.
Dosage
Standard Dosage
Adults:
- VTE Prophylaxis (Surgical):
- General surgery: 2500 IU SC daily for 7-10 days.
- Orthopedic surgery: 3500 IU SC daily for 7-10 days.
- VTE Prophylaxis (Non-surgical): 2500 IU (moderate risk) or 3500 IU (high risk) SC daily. Duration depends on the risk period.
- DVT Treatment: 115 IU/kg SC once daily for 5-9 days, or until adequate oral anticoagulation is established.
Children:
Use is not recommended due to insufficient data on safety and efficacy.
Special Cases:
- Elderly Patients: No dose adjustment necessary unless significant renal impairment is present.
- Patients with Renal Impairment:
- Mild to moderate: No dose adjustment generally required; monitor closely.
- Severe: Dose adjustment may be necessary; close monitoring essential.
- Patients with Hepatic Dysfunction: Limited data; caution advised; dose adjustment may be required.
Clinical Use Cases
Dosing follows standard guidelines for VTE prophylaxis and treatment in settings like intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations. Individual patient risk factors should be taken into account, with dose adjustments as needed based on renal function, hepatic function, and bleeding risk.
Dosage Adjustments
Dose modification necessary in patients with severe renal impairment. Close monitoring and dose adjustment may be necessary with hepatic impairment.
Side Effects
Common Side Effects
- Hematoma/ecchymosis/pain/itching at the injection site
- Bleeding (minor bruising to major hemorrhage)
Rare but Serious Side Effects
- Heparin-induced thrombocytopenia (HIT)
- Allergic reactions (rash, pruritus, anaphylaxis)
- Spinal or epidural hematoma (if neuraxial anesthesia or spinal puncture is performed)
- Osteoporosis (with long-term use)
Long-Term Effects
Osteoporosis.
Contraindications
- Hypersensitivity to bemiparin, heparin, or pork products
- Active major bleeding
- History of HIT
- Severe hepatic impairment
- Recent surgery/trauma to CNS, eyes, ears
Drug Interactions
Drugs that increase bleeding risk (e.g., NSAIDs, aspirin, warfarin, other anticoagulants, antiplatelet agents, SSRIs, SNRIs) may interact with bemiparin. Herbal and dietary supplements with anticoagulant properties should be avoided.
Pregnancy and Breastfeeding
Data on bemiparin use in pregnancy are limited. Use only if clearly necessary. Breastfeeding is not recommended due to insufficient data regarding bemiparin excretion in breast milk.
Drug Profile Summary
- Mechanism of Action: Accelerates antithrombin III activity, inhibiting Factor Xa and IIa.
- Side Effects: Bleeding, injection site reactions, HIT (rare), allergic reactions (rare).
- Contraindications: Hypersensitivity, active bleeding, HIT history, severe hepatic impairment.
- Drug Interactions: Other anticoagulants, antiplatelet agents, NSAIDs.
- Pregnancy & Breastfeeding: Limited data; caution advised/not recommended.
- Dosage: See Dosage section above.
- Monitoring Parameters: Platelet count, signs of bleeding, anti-Xa levels (if clinically indicated).
Precautions
- Avoid IM injections.
- Caution in patients with renal impairment, liver disease, history of bleeding disorders, uncontrolled hypertension.
- Monitor for signs and symptoms of bleeding and thrombocytopenia.
FAQs
Q1: What is the recommended dosage for Bemiparin?
A: Dosage depends on the indication. See Dosage section above for details.
Q2: How is Bemiparin administered?
A: Subcutaneously.
Q3: Can Bemiparin be used in pregnant women?
A: Use with caution and only if the potential benefit outweighs the risk. Insufficient data exists regarding its safety in pregnancy.
Q4: Is Bemiparin safe for breastfeeding mothers?
A: Breastfeeding is not recommended.
Q5: What are the main side effects of Bemiparin?
A: Bleeding and injection site reactions.
Q6: What drugs interact with Bemiparin?
A: Other anticoagulants, NSAIDs, antiplatelet agents.
Q7: What should be monitored in patients receiving Bemiparin?
A: Platelet counts, signs of bleeding.
Q8: What is the mechanism of action of Bemiparin?
A: It enhances the activity of antithrombin III, primarily inhibiting Factor Xa.
Q9: How is Bemiparin different from unfractionated heparin?
A: Bemiparin is a LMWH with a more predictable anticoagulant response, lower risk of HIT, and longer half-life, allowing for once-daily dosing.
Q10: What are the contraindications to using bemiparin?
A: Active major bleeding, history of HIT, severe hepatic impairment, hypersensitivity.
