Complications During Hospitalization

Advantages of LMWH vs Unfractionated Heparin

• Hospitalization not required
• No monitoring of APTT or PT required
• Rapid absorption from subcutaneous tissue; heparin’s absorption is more variable
• Bioavailability 90%; Heparin’s BA- 30%
• No hepatic metabolism resulting in longer half-life; less frequent dosing

Warfarin

Use:
Prophylaxis and treatment of venous thrombosis, pulmonary embolism, and other thromboembolic disorders.

MOA:
Interferes with the synthesis of vitamin K dependent coagulation factors
(II, VII, IX, X)

Dose:
Initially, 2-5 mg with dosing adjustments based on INR; Target INR 2-3 Adverse Reactions: bleeding, skin lesions, anorexia, nausea, vomiting

Drug Interactions:
CYP2C8, 2C9, 2C18, 2C19, 3A4 enzyme substrates

Monitoring:
INR, hematocrit

Managing INR changes:

• INR >3 and = 5 – Omit next doses and restart when INR approaches appropriate level

• INR >5 and = 9.0 – Omit 1-2 doses and restart at a lower dose or omit dose and give 1-2.5 mg Vitamin K

• INR >9 and < 20.0 – Stop warfarin. Give Vitamin K 3-5mg orally; Monitor INR

• Rapid reversal (INR>20.0) – Stop warfarin. Give Vitamin K 10mg slow IV infusion. Repeat every 12 hours or give fresh plasma transfusions.

 

 

 

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References

This information is for educational purposes only and is not a substitute for formal education or training. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient's medical history.

Last Updated: April 24, 2003