math problem...

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The antihistamine diphenhydramine (Benadryl) has been prescribed for a child weighing 35 pounds. The bottle label reads 5gm/1m.

How many mL should be prepared if the prescriber orders 1.25 mg/kg po?

Can somebody please help me to figure this out? The answer key is giving 3.98 or 4 ml..... however, I am coming up with 0.00398

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First of all, is it a typo that you have 5 gm in 1 ml? I am thinking you mean 5 mg, right?

Your first step is to change 35 lbs into kg, divide 35 by 2.2 to get 16.

The doctor has prescribed1.25 mg for every kg, so multiply 1.25 x 16 to get 20 mg. 20 mg is what you will plug into your problem.

Then I set up a ration and proportion problem,

5 mg/1 ml = 20 mg/x ml

The answer comes out to 4 ml to administer.

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I am not sure if it is a typo. It was on a math sheet that we were supposed to complete, and it is driving me nuts.

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the answer comes out correct for mg, so I think it must be!

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That makes perfect sense. Thank you so much. I will let the rest of the class know there was a typo, as we are all losing our minds.

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