What is the management for a patient with elevated INR on Acitrom (Acenocoumarol) for MS with AF?

Management of a Patient with INR 7 on Acitrom for MS with AF

For a patient with INR 7 on Acitrom (acenocoumarol) for mitral stenosis with atrial fibrillation, withhold Acitrom and administer oral vitamin K 2.5 mg to rapidly reduce the INR to therapeutic range (2.0-3.0). 1

Initial Management

1. Immediate actions:

   • Withhold Acitrom (acenocoumarol) immediately
   • Administer oral vitamin K 2.5 mg (low dose)
   • Check for signs of bleeding (both overt and occult)
   • Investigate potential causes of elevated INR

2. Laboratory monitoring:

   • Recheck INR in 24 hours
   • Target INR 2.0-3.0 for patients with MS and AF 2

Risk Assessment

The risk of major bleeding increases significantly when INR exceeds 4.5 and rises steeply above 6.0 1. With an INR of 7, this patient is at high risk for hemorrhagic complications, requiring prompt intervention even without active bleeding.

Factors to consider:

• Patient's age (elderly patients have higher bleeding risk)
• Concomitant medications (potential drug interactions)
• Recent dietary changes affecting vitamin K intake
• Renal and hepatic function

Detailed Management Algorithm

For non-bleeding patients with INR 7:

1. Day 1:

   • Hold Acitrom dose
   • Administer oral vitamin K 2.5 mg
   • Monitor for signs of bleeding
   • Check INR in 24 hours

2. Day 2:

   • If INR still >4: Consider additional low-dose oral vitamin K (1-2.5 mg)
   • If INR 3-4: Continue to hold Acitrom
   • If INR <3: Consider resuming Acitrom at lower dose than previous

3. Day 3 and beyond:

   • Resume Acitrom at 25-50% reduced dose once INR <3.0
   • Monitor INR every 2-3 days until stable in therapeutic range
   • Adjust dose as needed to maintain target INR 2.0-3.0

Special Considerations

For patients with MS and AF:

• Target INR should be 2.0-3.0 as recommended by American College of Cardiology/American Heart Association guidelines 2
• For patients with mechanical heart valves, target INR may need to be higher (2.5-3.5) 2

Potential causes of elevated INR to investigate:

• Drug interactions (antibiotics, antifungals, amiodarone)
• Reduced vitamin K intake
• Acute illness, especially with fever or diarrhea
• Liver dysfunction
• Excessive alcohol consumption

Resumption of Anticoagulation

Once INR returns to therapeutic range:

1. Resume Acitrom at a reduced dose (25-50% lower than previous)
2. Monitor INR more frequently initially (every 2-3 days)
3. Gradually adjust dose to maintain target INR 2.0-3.0
4. Educate patient on:
   • Consistent vitamin K intake in diet
   • Medication adherence
   • Avoiding alcohol excess
   • Signs of bleeding to watch for

Pitfalls to Avoid

1. Do not administer high doses of vitamin K (>5 mg) as this may cause prolonged resistance to Acitrom when therapy is resumed
2. Do not use subcutaneous vitamin K, as it is relatively ineffective 3
3. Do not restart Acitrom at the previous dose once INR normalizes
4. Do not delay INR monitoring after intervention
5. Do not use fresh frozen plasma for non-bleeding patients with elevated INR, as it carries risks without clear benefit 1

Long-term Considerations

After stabilizing the patient's INR:

• Review and optimize anticoagulation management
• Consider more frequent INR monitoring if patient has had recurrent episodes of supratherapeutic INR
• Evaluate if patient would benefit from anticoagulation clinic referral
• Consider whether the patient might be a candidate for direct oral anticoagulants (DOACs), though these are contraindicated in mitral stenosis with AF 2