Discuss NABP NAPLEX Exam Topic 1 Question 16

A physician needs your help to calculate the protamine dose on a patient who started hemorrhaging while on heparin. Patient has been receiving heparin at a dose of 13mls/hr for 2 hrs when the physician decides to use protamine to reverse the heparin. Heparin bag says concentration of 50 units/ml. The half-life of heparin is 60 minutes. 1 mg of protamine reverses 100 units of heparin.

How much protamine should be given to this patient?

Suggested Answer: E

1st hour: 13mL/hr 1 hr = 13mL 50U/mL = XU/13mL 650U Heparin given in hours since the half-life of protamine is 60 min 2nd hour 650/2 =325 units 650 units + 325 units = 975 units needs to be reversed.

**1mg of protamine reverses 100U of Heparin (1mg protamine/100U Heparin) = (x mg protamine/975U Heparin given) = x = 9.7mg protamine

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12 comments · newest first

Domingo 11 months ago

Definitely going with 13mg based on the calculations!

Portia 12 months ago

Wait, are we sure about that half-life? Sounds off to me.

Misty 12 months ago

I thought it was 10mg, but I guess the math checks out.

Haley 12 months ago

1300 units means you need 13mg of protamine, right?

Tammara 1 year ago

Heparin dose was 13ml/hr for 2 hrs, so that's 1300 units.

Chantell 1 year ago

If I recall correctly, the total heparin given is 1300 units, so that would mean we need 13 mg of protamine, but I’m not completely sure about the math.

Irma 1 year ago

I feel a bit confused about the heparin half-life and how it affects the calculation. Should we account for that in the total dose?

Lanie 1 year ago

I think we practiced a similar question where we had to reverse heparin with protamine. I believe it's 1 mg of protamine for every 100 units of heparin, right?

Magdalene 1 year ago

I remember that we need to calculate the total heparin given first, but I'm not entirely sure how to do that with the rate and time.

Jennie 1 year ago

This question seems straightforward, but I want to double-check the key details to make sure I understand it correctly.

Roslyn 1 year ago

I've seen questions like this before. I'll apply the same logic I used last time and see if I can figure it out.

Bea 1 year ago

This one seems pretty straightforward. I think the Programme Manager would be the one responsible for improving the wording of the Vision Statement to provide greater clarity.

NABP NAPLEX Exam - Topic 1 Question 16 Discussion