Usage
Reviparin is an anticoagulant, specifically a low molecular weight heparin (LMWH). It is prescribed for the prevention of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), in patients undergoing certain types of surgery, particularly orthopedic procedures like hip or knee replacements. It is also used in some cases for the treatment of established VTE and for prophylaxis in medical patients at risk for thromboembolism.
Alternate Names
The generic name is reviparin sodium. Clivarin is a common brand name.
How It Works
Pharmacodynamics: Reviparin primarily works by accelerating the rate at which antithrombin inhibits factor Xa. This inhibition reduces the conversion of prothrombin to thrombin, thereby decreasing the formation of fibrin clots. It has less of an effect on thrombin (Factor IIa) and platelet function than standard unfractionated heparin.
Pharmacokinetics: Reviparin is administered subcutaneously. Its bioavailability is close to 100%. Peak anti-Xa activity is achieved within 4-5 hours. It has a half-life of about 5-6 hours. It is primarily cleared through renal mechanisms.
Mode of Action: Reviparin binds to antithrombin, a naturally occurring anticoagulant. This binding enhances the activity of antithrombin, specifically its ability to inactivate factor Xa, a key enzyme in the coagulation cascade.
Dosage
Standard Dosage
Adults:
- VTE Prophylaxis (Surgical): 3436 IU (0.6 mL) subcutaneously once daily, starting 12 hours before surgery for high-risk procedures (e.g., major orthopedic surgery). For lower-risk procedures, 1432 IU (0.25 mL) subcutaneously once daily, starting 2 hours preoperatively or at the start of immobilization.
- VTE Treatment: 175 IU/kg once daily subcutaneously. Dosage may be adjusted based on anti-Xa levels.
Children:
- Pediatric patients above 3 months: 30 IU/kg twice daily subcutaneously.
- Pediatric patients under 3 months: 50 IU/kg twice daily subcutaneously.
- Monitor anti-Xa levels to adjust dosage as needed. Pediatric dosing should always be guided by expert consultation and close monitoring.
Special Cases:
- Elderly Patients: Caution is advised, particularly for frail individuals or those with low body weight. Renal function should be assessed.
- Patients with Renal Impairment: Contraindicated in severe renal impairment (creatinine clearance < 30 mL/min). Dose adjustments are necessary in moderate renal impairment.
- Patients with Hepatic Dysfunction: Caution is advised. Close monitoring is recommended.
- Patients with Comorbid Conditions: Use with caution in patients with conditions that increase bleeding risk.
Clinical Use Cases
- Surgical Procedures (especially orthopedic): Used for VTE prophylaxis.
- Trauma: Used in immobilized trauma patients at risk of VTE.
Dosage Adjustments
Dose adjustments are based on anti-Xa levels and renal function. Consult specific guidelines for adjustments in renal impairment.
Side Effects
Common Side Effects
- Bleeding (minor)
- Bruising
- Pain at injection site
- Hematoma
Rare but Serious Side Effects
- Major bleeding
- Heparin-induced thrombocytopenia (HIT)
- Spinal or epidural hematoma (with neuraxial anesthesia)
- Allergic reactions
Long-Term Effects
Osteoporosis with long-term use.
Contraindications
- Hypersensitivity to reviparin or other LMWHs or heparin.
- Active major bleeding.
- Severe thrombocytopenia.
- Conditions with high bleeding risk (e.g., uncontrolled hypertension, bacterial endocarditis).
- Severe renal impairment.
- Concurrent lumbar puncture, spinal, or epidural anesthesia.
- Neonates, especially premature infants.
Drug Interactions
- Anticoagulants (e.g., warfarin): Increased bleeding risk.
- Antiplatelet agents (e.g., aspirin): Increased bleeding risk.
- NSAIDs: Increased bleeding risk.
Pregnancy and Breastfeeding
- Pregnancy: Use with caution. Insufficient data to determine safety.
- Breastfeeding: Limited data suggests it’s likely safe, but caution is advised. Monitor infant for signs of bleeding or bruising.
Drug Profile Summary
- Mechanism of Action: Enhances antithrombin activity, inhibiting Factor Xa.
- Side Effects: Bleeding, bruising, injection site reactions, HIT, spinal hematoma.
- Contraindications: Hypersensitivity, active bleeding, severe thrombocytopenia, severe renal impairment.
- Drug Interactions: Anticoagulants, antiplatelet agents, NSAIDs.
- Pregnancy & Breastfeeding: Use with caution. Limited data.
- Dosage: See detailed dosage guidelines above.
- Monitoring Parameters: Anti-Xa levels, complete blood count (CBC), signs of bleeding.
Popular Combinations
Reviparin is typically not used in combination with other anticoagulants for VTE prophylaxis.
Precautions
- Monitor for signs of bleeding.
- Use cautiously in patients at increased risk of bleeding.
- Avoid IM injections.
- Renal function assessment is essential.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Reviparin?
A: See detailed dosage guidelines above. It varies depending on indication, age, and renal function.
Q2: How is Reviparin administered?
A: Subcutaneously.
Q3: What is the mechanism of action of Reviparin?
A: Reviparin primarily enhances the activity of antithrombin III, leading to inhibition of Factor Xa.
Q4: What are the major contraindications to Reviparin use?
A: Active major bleeding, severe thrombocytopenia, hypersensitivity to reviparin or other LMWHs, severe renal impairment.
Q5: What are the common side effects of Reviparin?
A: Bleeding, bruising, pain and hematoma at the injection site.
Q6: How should Reviparin dosage be adjusted in renal impairment?
A: Dosage adjustments are necessary based on the degree of renal impairment. Consult specific guidelines for dose adjustment in renal impairment. Contraindicated in severe renal impairment.
Q7: Can Reviparin be used during pregnancy?
A: Use with caution in pregnancy only if the benefit outweighs the risk. Data on safety in pregnancy is limited.
Q8: Can Reviparin be used during breastfeeding?
A: Limited data suggests it is likely safe, but caution is recommended. Monitor infant for signs of bleeding or bruising.
Q9: What is the antidote for Reviparin overdose?
A: Protamine sulfate can partially reverse the anticoagulant effects of reviparin.
Q10: How is Reviparin monitored?
A: Monitor anti-Xa levels, CBC, and clinical signs of bleeding.
