Dosage Calc


  • Specializes in lots of different areas. Has 17 years experience.

Hey all. I know there is an assistance board for dosage calc somewhere, but thought this might be viewed a little more here. I will be done with my RN program in December, need to make it through ONE MORE math test. I did all the practice problems without a problem, except for two. I have no idea really how to set these up. I know how to do conversions, drip factors, etc. but how in the world do i set these up?

1. The pt. has a dopamine drip running at 40mL/hr. The dopamine comes as 400mg in 500mL D5W. The patient weighs 68kg. How many mcg/kg/min is this patient receiving?

I know that 400mg=400,000mcg

2. The order reads Oncovin 1.3 mg IV q Monday. The child is 52 inches tall and weighs 40 lbs. The recommended dosage is 1.5-2 mg/m2/day. Is the dose safe? Explain your answer.

thanks in advance,



7 Posts

I love it when you guys post Med math stuff! It gets me thinking Now, this is coming from a Freshman Nursing Student, but I'm pretty sure I'm right. Here's the site to check out:

Practice the formulas, on this page, and the Answer for 1 should be 7.8 mcg/kg/min.

Okay, number 2 is a pain and a half :uhoh3: Now I'm basing this off of the "recommended dosage" being the adult recommended dosage. And if that's the case, "No" that is not a safe dose. The safe range would be between .75mg/m2/day and .99mg/m2/day.

Here's the link I used. I could be using the wrong formula, so let me know if I did:

Hope I helped! And if I'm wrong PLEASE tell me. I want to learn! :bowingpur

montinurse, BSN

220 Posts

Specializes in lots of different areas. Has 17 years experience.

you were right on for the first one. for the second, the dose range was 1.21 mg-1.62 mg. It was on some table in our book. still need to find it. but i guess it was a safe pedi range.

I have 6 wks left of my LPN-RN transition, and they didn't teach us dosage calc! I took a one credit course at the beginning of my LPN training, and that benefited me greatly! I really get hung up on the mcg/kg/min when i have to use other formulas that I'm not too familiar with. Thanks for your reply. Our first test is tomorrow. We have to score a 90% or above. If we don't, I think we have two more chances and then we fail out. SOO fun. Too much pressure along with everything else!

Thanks again. Let me know if you need help in the future..:yeah:


7 Posts

Thanks, will do. And good luck on your test tomarrow ^^ We just had our basic calc test for oral meds. I bombed the mg in a grain questions, but still managed to pull through with a 90%. Yea I was dumbfounded when I looked at those formulas for #2. I'll get to that point eventually. Now I'm getting some shuteye for clinicals tomarrow. Take care, and again, GL!

This topic is now closed to further replies.