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Warfarin Inpatient Nomogram including dose prediction equation

>Beta<  Version 1.0  - Date: July 2013
All calculations must be confirmed before use. The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgment. Neither GlobalRPh Inc. nor any other party involved in the preparation of this program shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any user's use of or reliance upon this material.PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER.   Read the disclaimer
Patient Parameters
Age:      Specify race:  
Height
:     Weight:
Other (used to predict maintenance dose):
Target INR   Patient receiving amiodarone:  
 Smoker:    DVT /PE present?:

Starting Dose:

Usual starting dose for most patients: 5 mg (Usual range: 4 -10 mg)

Select starting dose:     mg   (Return to this form if you need to alter the dose)
  
9th ACCP suggestion:   Patients healthy enough to be treated as outpatients:  Give warfarin 10 mg daily x 2 days. Further dosing should be based on INR monitoring. (Preferred to starting with an estimated maintenance dose.)   (Grade 2C)

9th ACCP suggestion:   Patients with acute VTE should be started on warfarin on day 1 or 2 of LMWH or heparin therapy e.g. do not wait several days to start treatment.  (Grade 2C)


9th ACCP suggestions:  

-For pt's started on UFH:  Use weight-adjusted  initial bolus of 80 units/kg followed by 18 units/kg per hour for VTE;   or  bolus of 70 units/kg  followed by 15 units/kg per hour for cardiac or stroke patients) or use of a fixed dose (bolus 5,000 units followed by 1,000 units/hour) rather than alternative regimens (Grade 2C) .

-For outpatients with VTE treated with subcutaneous UFH: use weight-adjusted dosing (first dose 333 units/kg, then 250 units/kg) without monitoring rather than fixed or weight-adjusted dosing with monitoring (Grade 2C) .

-For patients receiving therapeutic LMWH who have severe renal-insufficiency (calculated CRCL <30 mL/min): Dose reduction is preferred rather than using standard doses (Grade 2C) .

-Pt's with VTE and body weight > 100 kg: fondaparinux  treatment dose should be increased from the usual 7.5 mg to 10 mg daily SC (Grade 2C) .

Source:
Holbrook A, Schulman S, Witt DM, Vandvik PO, Fish J, Kovacs MJ, Svensson PJ, Veenstra DL, Crowther M, Guyatt GH; American College of Chest Physicians.  Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.   Chest. 2012 Feb;141(2 Suppl):e152S-84S. doi: 10.1378/chest.11-2295.

Equations  Used:

BSA

1]  (Weight) kg0.425 x   (Height) cm0.725 x  0.007184 = BSA in M2
    
Reference
: DuBois D, DuBois DF. A formula to estimate the approximate surface area if height and weight be known. Arch Int Med 1916;17:863-71.




Warfarin Dose Prediction

2]   exp [0.613 + (0.425 x BSA) - (0.0075 x age)  + (0.156 x African-American race)
            + (0.216  x target INR) - (0.257 x amiodarone) + (0.108  x smokes) 
                + 0.0784  x  DVT/PE ]

Reference:  Gage BF, Eby C, Johnson JA, Deych E, Rieder MJ, et al. Use of pharmacogenetic and clinical factors to predict the therapeutic dose of warfarin. Clin Pharmacol Ther. 2008 Sep;84(3):326-31. Epub 2008 Feb 27.


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Disclaimer

All calculations must be confirmed before use. The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgment. Neither GlobalRPh Inc. nor any other party involved in the preparation of this program shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any user's use of or reliance upon this material.PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER.   Read the disclaimer
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