Calculation

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A desired dose for crystapen is 2.5 Mg, Q.i.d per 24 hours. If a drug on hand is 5iu.

Find the one dose

Specializes in Pharmacy, Mathematics, Physics, and Educator.

I am just curious who made up this question.

I am just curious who made up this question.

This is so weird! I never had an IU question like this!!

I've never even heard of Crystapen? I looked it up and it says its benzylpenicillin:

Benzylpenicillin sodium (a derivative of Benzylpenicillin) is reported as an ingredient of Crystapen in the following countries:

  • Canada
  • Malta
  • United Kingdom

Is that correct? So, this isn't a brand in the U.S? Would this be Penicillin G Sodium in the U.S.?

Specializes in Pharmacy, Mathematics, Physics, and Educator.

I don't think this brand is available in the US. It is available in 600 mg vials which is equivalent to 1,000,000 units. That dose would be maybe appropriate for a grasshopper. Also, you would need to know how the 5 units was reconstituted. Just a dumb question that only served to cause confusion for the poor students.

I don't think this brand is available in the US. It is available in 600 mg vials which is equivalent to 1,000,000 units. That dose would be maybe appropriate for a grasshopper. Also, you would need to know how the 5 units was reconstituted. Just a dumb question that only served to cause confusion for the poor students.

I don't think it is either. I found the 600 mg vial equivalent to 1,000,000 units and I did the calculations and came up with 0.003 mg as the answer. I then used the site Wuzzie gave and it gave the same thing that I came up with (0.003 mg). Not sure if that's right because this is definitely a dumb confusing question! I really wish instructors would try harder to make more REAL WORLD examples for students!

Specializes in Pharmacy, Mathematics, Physics, and Educator.

Well, the dose was 2.5 mg which is 4167 units or 833 of the 5 unit "on hand" vials, which does not make sense. The correct answer is 'Find one dose my a**. I will find one dose when you learn to write a dosage calculation problem that makes sense.

Thanks for your contributions

Based upon some of the problems posted here, it seems that more and more instructors are writing some really strange medication math problems. What's unclear is whether they do this because they are too lazy to take the time to research the medication as to dosing parameters and how supplied, or they think that if the student can solve some of these ridiculous problems they should be able to easily solve real world problems. Regardless, I think it unfair to the student when they do this, and agree that the assigned problems should reflect what the student will be doing in the real world.

OP, if you haven't done so, you really should search bjwojcik's posts and download a copy of the textbook that he wrote; I think you will find it most helpful.

Best wishes.

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