Heparin/Lovenox Dosing Guidelines 

Heparin Dosing
Guidelines 


PTT 
Dose 
Next aPTT 


Initial dose 
80 units/kg bolus, then 18 units/kg/hour 



< 35
seconds (< 12x control) 
80 units/kg bolus, then increase
rate by 4 units/kg/hour 
6 hours (assume steady state kinetics) 










3545 seconds
(1.21.5x control) 
40 units/kg bolus, then increase
rate by 2 units/kg/hour 
6 hours 










4670 seconds
(1.52.3x control) 
No change 
6 hours 


7190 seconds
(2.33x control) 
Decrease rate by 2 units/kg/hour 
6 hours 


> 90
seconds (> 3x control) 
Hold infusion for 1 hour, then
decrease rate by 3 units/kg/hour 
6 hours 












Lovenox Dosing
Guidelines 



Condition Treating 
Dosing 
Renal Dosing 
Hip/Knee Surgery 
30mg subcutaneously every 12 hours 
30mg subcutaneously once daily 
Hip Replacement 
40mg subcutaneously once daily 
30mg subcutaneously once daily 
Abdominal Surgery 
40mg subcutaneously once daily 
30mg subcutaneously once daily 
Treatment of Outpatient DVT 
1mg/kg subcutaneously every 12 hours 
1mg/kg subcutaneously once daily 
Treatment of Inpatient DVT 
11.5mg/kg subcutaneously once daily 
1mg/kg subcutaneously once daily 
Unstable Angina or Non QWave MI 
1mg/kg subcutaneously every 12 hours 
1mg/kg subcutaneously once daily 



Heparin Overdosage
Treatment Guidelines 


Following Intravenous Administration 


Since blood heparin concentrations decrease rapidly after
administration, adjust the protamine dosage depending upon the duration of
time since heparin administration as follows: 




Time Elapsed 
Protamine Dose (mg) needed to Neutralize 100 units of Heparin 


Immediate 
11.5mg 


3060 minutes 
0.50.75mg 


> 2 hours 
0.250.375mg 



Following Subcutaneous Administration 


11.5mg of
protamine per 100 units of heparin; this may be done by a portion of the dose
(ex. 2550mg) given slowly intravenously, followed by the remaining portion
as a continuous infusion over 816 hours (the expected absorption time of the
subcuteneous heparin dose) 






Low Molecular
Weight Heparin Overdosage Guidelines 


Note: Antifactor Xa activity never completely
neutralized (maximum: ~6075%) 



Enoxaparin
(Lovenox): 1mg protamine for each mg of enoxaparin; if PTT prolonger 24
hours after first dose, consider additional dose of 0.5mg for each mg of
exonaparin 





Dalteparin
or Tinzaparin: 1mg protamine for each 100 antiXa IU of dalteparin or
tinzaparin; if PTT prolonged 24 hours after initial dose, consider
additional dose of 0.5mg for each 100 antiXa IU of dalteparin or tinzaparin 





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