Initiation of warfarin

The Fennerty regimen is only for rapid initiation of warfarin (caution in elderly) and is valid for the first 4 days of warfarin treatment only.

Day

INR

(check at 9-11am)

Warfarin (mg)

(give at 5-7pm)

1 <1.4 10
2

<1.8

1.8

>1.8

10

1

0.5

3

<2.0

2.0-2.1

2.2-2.3

2.4-2.5

2.6-2.7

2.8-2.9

3.0-3.1

3.2-3.3

3.4

3.5

3.6-4.0

>4.0

10

5

4.5

4

3.5

3

2.5

2

1.5

1

0.5

0

   

Predicted maintenance dose

4

<1.4

1.4

1.5

1.6-1.7

1.8

1.9

2.0-2.1

2.2-2.3

2.4-2.6

2.7-3.0

3.1-3.5

3.6-4.0

4.1-4.5

>4.5

>8

8

7.5

7

6.5

6

5.5

5

4.5

4

3.5

3

Miss 1 day then give 2mg

Miss 2 days then give 1mg

 

Reversal of warfarin

Secondary care NHS Lothian guidelines for reversal of patients on warfarin and for the use of Beriplex can be found on the Intranet - click on the links below

http://intranet.lothian.scot.nhs.uk/Directory/Haematology/policy/Documents/Warfarin%20Reversal.pdf

http://intranet.lothian.scot.nhs.uk/NHSLothian/Healthcare/A-Z/Haematology/policy/Documents/Beriplex%20Administration.pdf

 

Primary care guidelines for warfarin

“Prescribing guidelines for the management of patients on warfarin in primary care, February 2018” is available in full, and summary format:

Full guideline

http://intranet.lothian.scot.nhs.uk/Directory/unscheduledcareservice/all%20files/Prescribing%20Guidelines%20for%20the%20Management%20of%20Patients%20on%20Warfarin%202018.pdf

Summary guideline

http://intranet.lothian.scot.nhs.uk/Directory/unscheduledcareservice/all%20files/Guidelines%20for%20the%20management%20of%20patients%20on%20warfarin%20Feb18.pdf

 

Safe prescribing of warfarin at time of discharge

Before discharge ensure the patient is given a completed yellow anticoagulant booklet, counselled about warfarin (contact pharmacist), and ensure timely notification to GP. Please ensure that the appropriate section on the immediate discharge summary is completed.