I feel hopeless that I can't figure this out

nurseprnRN, BSN, RN · Jul 10, 2014

a solution of D5W containing 25 mg of a drug is to infuse in 30 min. The dosage range is 4-8 mg/kg/day every 6 hours. The child weighs 18.7 kg.
what is the dosage range per day? I got 74.8---149.6 mg/day
daily dosage ordered? Hmmmm... I don't know what to do??
assessment (which I think their asking is it in the dosage range)

This is one of those times when you have to stop and look at what they're really asking you, and what words are completely irrelevant.

In your case, you have gotten it right at the beginning-- the total dose is 4-8mg/kg/day, and you have correctly multiplied 18.7 kg x both 4 (total is 74.8mg) and 8 (total 149.6 mg). So that's your therapeutic dose range for the day.

So the therapeutic daily dose range is 74.8mg - 149.6mg. And if all they are asking you for is the DAILY DOSE RANGE, then you're done.

If you want to know what the therapeutic dose is for q6h, there are four of those in a day, so you would divide the 74.8 and the 149.6 by four to give you the q6h dose. That would be, umm, 18.7mg to 37.4mg.

Now, if their question is, "The q6h dose is 25mg (it doesn't matter how long it infuses over or in how much fluid, those are just in there to mess with your head). Is this in the therapeutic range?" all you need to know is "Is 25mg somewhere between 18.7mg and 37.4mg?"

Or you could skip the divide-by-four and say, "Is 4 x 25mg (the daily dose) somewhere between 74.8mg and 149.6mg (the daily therapeutic dose range)?"

Do you see how that works?

Mrs2016 · Jul 10, 2014

I was thinking that too, but the answer in my book says 100 mg/day, so I'm like WTH!!??

nurseprnRN, BSN, RN · Jul 10, 2014

I was thinking that too, but the answer in my book says 100 mg/day, so I'm like WTH!!??

So apparently, they are asking what the daily dose is if the single dose is 25mg (which is in your first sentence) . That's your four doses x 25mg, for a total daily dose of 100mg. Are you sure you have correctly quoted the problem here in its entirety?

Mrs2016 · Jul 10, 2014

Yes I did. I typed it out word, for word. Confusing right? I know I am :confused:

Esme12, ASN, BSN, RN · Jul 10, 2014

Ok...yes it is confusing. Another poorly worded question

They want several answers.

You need to give a med.

The dosage range for this med is 4-8 mg/kg/day every 6 hours in a solution of D5W[to infuse over 30 min(not needed for the question)].

The child weighs 18.7 kg. The dosage range for this med is 4-8 mg/kg/day is the standard. You have a solution of D5W containing 25 mg of a drug. You need to give this drug every 6 hours.

What is the dosage range per day for this drug? 4 mg/kg/day x 18.7 kg = _____ and 8mg/kg/day x 18.7 = ____

What is the daily dosage ordered? If you are giving 25mg ever six hours (that is 4 doses of 25mg in a 24 hour time period) How much are you giving total? total of med administered in 24 hours 25mgs x 4 doses = _____

assessment ...hummmm I'm not sure. Probably assess whether or not this ordered dose of 25mg every 6 hours is within the recommended 4-8mg/kg/day.

classicdame, MSN, EdD · Jul 21, 2014

I recommend you purchase a math-for-meds workbook - the kind that has loads of problems for you to work out. After a while you will see the patterns and it will begin to click. Good luck!