Med math help?!

Qteapi · Oct 2, 2015

You might want to show us your work first and then we know what is tripping you up and how to help

EricaAngela90 · Oct 2, 2015

I would first divide your mg/day answer in half then figure out how many tablets per dose and x2 would be day

kyoung4321 · Oct 2, 2015

100 lbs * 1kg/2.2lbs * 30mg/1kg=1,363mg

1,363 mg / 2 = 681.5mg

681.5mg/500mg = 1.363 tablets

would I still have to multiply by 2 and why?

SopranoKris, MSN, RN, NP · Oct 2, 2015

The key to always getting the right answer is to set up your equation with the unit you need on top. In this case, the question is asking tablets/dose. So, start there.

(1 tablet/500 mg) Ã— (30 mg/kg day) Ã— (1 kg/2.2 lbs) x (100 lbs) x (1 day/2 doses)

When you cancel out your units, you're left with tablets per dose. Make sense?

Now do the math and tell me what you got for an answer :)

kyoung4321 · Oct 2, 2015

I got 1.36 tablets. So, would I round to 1 or 1.5?

Thank for the help

SopranoKris, MSN, RN, NP · Oct 2, 2015

I got 1.36 tablets. So, would I round to 1 or 1.5?
Thank for the help

Did the question say to round up? 1.36 rounds up to 1.4. Can you administer 1.4 of a tablet?

Mavrick, BSN, RN · Oct 4, 2015

100 lbs * 1kg/2.2lbs * 30mg/1kg=1,363mg
1,363 mg / 2 = 681.5mg
681.5mg/500mg = 1.363 tablets
would I still have to multiply by 2 and why?

Here is where you made your mistake. You forgot to carry the unit "/day".

100 lbs * 1kg/2.2lbs * 30mg/1kg/day=1,363mg/day

Another question. Do the doses have to be equal?

chare · Oct 4, 2015

Here is where you made your mistake. You forgot to carry the unit "/day".

No mistake here. As the original question was "how many tablets per dose," the OP correctly worked the problem.

The question about multiplying be 2 was directed to a specific comment that she received in post number 2.

Mavrick, BSN, RN · Oct 4, 2015

The question about multiplying be 2 was directed to a specific comment that she received in post number 2.

The mistake was the OP didn't calculate the daily dose as post number 2 specifically stated. "I would first divide your mg/day answer in half then figure out how many tablets per dose and x2 would be day"

Everyone is also assuming an equally divided dose which the original problem doesn't state.

It will be tricky to get the correct dosage anyway using 500mg tablets. If your daily dose works out to 1363mg you could give one 500mg tablet then later give 1 1/2 500mg tablet to make a total of 1250mg. Not exactly the calculated dose but how accurate is .4 of a pill anyway?

chare · Oct 4, 2015

The mistake was the OP didn't calculate the daily dose as post number 2 specifically stated. "I would first divide your mg/day answer in half then figure out how many tablets per dose and x2 would be day"

Please reread the post from the OP that you quoted; the one where you were explaining her mistake. She arrived at the correct answer, as she was asked to determine the number of tablets for a single dose.

Everyone is also assuming an equally divided dose which the original problem doesn't state.
It will be tricky to get the correct dosage anyway using 500mg tablets. If your daily dose works out to 1363mg you could give one 500mg tablet then later give 1 1/2 500mg tablet to make a total of 1250mg. Not exactly the calculated dose but how accurate is .4 of a pill anyway?

Just as some are assuming that problems assigned in nursing school accurately reflect actual practice. According to several online sources (Drugs.com, American College of Rheumatology, Medscape, and RxList), sulfasalazine is not weight-based dosing.

Mavrick, BSN, RN · Oct 5, 2015

100 lbs * 1kg/2.2lbs * 30mg/1kg=1,363mg
1,363 mg / 2 = 681.5mg
681.5mg/500mg = 1.363 tablets
would I still have to multiply by 2 and why?

My post was an attempt to answer this question, not the question presented in the original post.

chare, I thought there was something funny about an order that required 1.363 tablets!