Doseage and Calculations can I do this????

Cali_Nurse_209 · Jun 23, 2012

I actually took a dosage calculation class in the summer of 2009 and just reviewed on it this month. The class is not that bad and totally doable. You'll need to know things like the metric system and how to calculate back in forth. For example lbs to kg, g to mcg. Also, oz to ml and things like that. Dividing/multiplication etc. Get familiar with dimensional analysis. A book I used to review was Dosage Calculations Demystified and a book called Math For Nurses. There are other helpful books out there. Since you took college algebra and received an A I think you'll do more than fine. Dosage calculations is pretty basic, @ least it was for me. You should stay with it because it'll be very beneficial for you in the nursing program.

k_girl153 · Jun 23, 2012

I was extremely nervous about taking this class too when I started school since it had been over 10 years from my last math class! But it was honestly the easiest class I'd ever taken. I ended up with a 99% in it.

It is all just basic math - addition, subtraction, multiplication, division. Cross multiplication is your friend! You will do fine in the class. My teachers broke the problems down step by step which made the class seem longer than it needed to be.

I highly suggest taking it. It's necessary for the program and you will be using it a lot as time goes on. Good luck!

girlswcurls · Jun 27, 2012

So today was my first class... it was awful. We did 5 chapters in 3 hours. Our math book does not break down dimensional analysis at all and I am struggling with it already. So tempted to withdraw and take it in 15 weeks instead. Just can't seem to get a grasp on things and our instructor is teaching this class for the FIRST time. She couldn't even figure out how to work the projector and won't hand out power point slides because she is afraid we won't come to class. REALLY? I want to do well, and am asking for her help by allowing me to "review" the slides because the book is skipping over some of the concepts she is teaching. AHHHHH.......

PinkCupcake · Jun 27, 2012

Dimensional analysis is cake once you get the hang of it I promise!

Let's say the order is Lanoxin 0.375 mg. I.M. and the label is Lanoxin 500mcg./2mL

Your equivalent is going to be 1000mcg = 1mg because the order is in mg but the label is in mcg

First start with the order

0.375mg

Then do your equivalent next

0.375mg x 1000mcg/1mg you want to make sure that your labels are diagonal from each other notice how the mcg is on top and the mg are diagonal from each other?

We only had one equivalent in this example but if you had more you'd move to the next one. Now we add in the label portion of the problem

0.375mg x 1000mcg/1mg x 2mL/ 500mcg again notice how the units are diagonal from each other. That will cancel them out so you will be left with only mL which will be your answers label.

Also remember that the first number in the problem is over one. I don't write it out that way but if it helps you could.

0.375mg x 1000mcg/1mg x 2mL/500mcg = 750/500 = 1.5mL

so what I did was multiply across the top. 0.375 x 1000 x 2 = 750 which is the top number

then multiply across the bottom, remember that the first number (0.375 is over 1 and can be written 0.375/1)

1 x 1 x 500 = 500 for the bottom number

divide the 750/500 and you get 1.5 and the label is in mL because that's how the medication is measured out

I hope this made sense. You could also try watching some youtube videos they help too. Good luck you can do this!!!

palmbeachRN · Jun 28, 2012

Congrats on your grade! I am an RN, coming up on 2 years cardiac experience. You definitely should take that dose calc class. We never had a separate class for it, but every semester we were required to take a 10-15 question test on dose calculations and if we got more than one wrong, we failed the semester. It is IMPERATIVE as an RN that you are able to calculate this. Computers are nice, but you have to understand the concept because the calculations won't always be available to you. TRUST me. Once you get the hang of it, you can solve any problem. I'm sure all the math you will do in the class is stuff you already know how to do, just with real-world examples. Especially if you've taken chemistry. Once you practice, you will be fail-proof, I promise. There are only a handful of types of dose calc problems, and once you get the hang of it, you're golden!!!!! Good luck.

palmbeachRN · Jun 28, 2012

Wow, just saw your post about the first class. When has the first class of ANY course ever been easy??!!! It's always overwhelming!!!! Hang in there!!!!! I'm sure your classmates are all thinking the same thing.

palmbeachRN · Jun 28, 2012

Another example, easy one. Just went over this with a new grad I'm precepting.

Order is Morphine 2mg IV.

The vial comes in the concentration of 5mg/mL ( in one mL, there are 5mg of the drug).

*Start with what you want!* (you want 2 mg!)

2mg X 1 mL

------>5 mg *5 mg is on the bottom, so the mg's cancel out*

(In order to set up the above, I had to make sure the units cancel out in the end. That's how you figure out how to set up any problem!!!!! Think about what you need to cancel out!)

*The "mg" cancel out* You are left with mL (which is what you are trying to figure out... how many mL do I draw up?)

2 X 1 mL

---->5 *mg cancel out*

Now just do the math, and you are left with the answer in mL!!!!

2 X (1/5) = 0.4

You would draw up 0.4 mL, and that would have 2 mg of the drug in it. Hope this helps, now or future.

Just always keep in mind what end product you are looking for... In this case you were looking for mL. Then, set up your problem accordingly to get the other units to cancel out, so you are left with what you're looking for!