Oral Dosages Help..

Mommy&RN, BSN, RN · Dec 18, 2013

1000/500=2

500x2=1000

500x4= 2000

NICUmiiki, DNP, NP · Dec 18, 2013

There is 500mg per 1 tablet which is the same as 1 tablet per 500mg.

The order is 1000mg per 1 dose.

The math would be...

1 tab/500 mg x 1000mg/1 dose

(Notice that the mg cancels out)

So after all the calculization....

2 tabs/dose

Esme12, ASN, BSN, RN · Dec 18, 2013

moved for best response

Andoo · Dec 18, 2013

Try to keep in mind, Doctors Order (DD) dosage on hand (DH), and quantity (Qt).

DD / DH * Qt

1000 / 500 * 1

1000 / 500 = 2

2 * 1 = 2 tablets.

NICUmiiki, DNP, NP · Dec 18, 2013

And there are different ways to solve a problem. I used dimensional analysis (to cancel out units) and a pp used a formula that you could memorize.

KelRN215, BSN, RN · Dec 18, 2013

1.Order amoxicillin 1000 mg p.o.t.i.d.
Available amoxicillin 500 mg tables how many tablets will you administer per dose?
I did the math 500/1000=2 per dose or 4 per dose?
But I need help:cry:

The math is 1000/500 which is 2. 500/1000 is 1/2. Each pill is 500 mg, how many do you need to administer to make 1000 mg? How much will the patient be getting if you administer 4 pills?

nurseprnRN, BSN, RN · Dec 19, 2013

You have to start right now looking at what the question is and how to eliminate the pieces of information they give you to distract you. That is what this question is about: Can you identify what you have to know to solve the problem, and what is extraneous?

See, so many people are eager to use a formula to solve dosage problems that they try to cram all the data they're given into the formula...and the people who write the test questions know that. So they put in information that has nothing whatsoever to do with the question being asked.

And then when they write the four possible answers, they are sure to put in at least one that, while erroneous, uses all those numbers, to trap the people who can't read a question for what's important. Knowing "What's important here?" is a critical skill in nursing.

Since the question being asked is, "How many tablets will you administer per dose?" it doesn't matter that they're to be given three times a day, once a week, or every ten minutes, does it? They aren't asking you how many tablets to get from the pharmacy for all the doses to be given in the day, just for one dose. All that matters is knowing how many 500 mg tablets make one 1000 mg dose. If you can't do that in your head, well ...

Pink Magnolia, BSN, RN · Dec 21, 2013

Tabs= 1 tab/ 500 mg x 1000 mg

= 2 tabs

Stella_Blue · Dec 21, 2013

Its always the amount desired divided by the amount that you have. If this were a volume question then you would also have to multiply x amount of mL afterwards but since it is not a simple desired/have and then you are done =)

Mainergal2000 · Dec 24, 2013

I agree with Miiki dimensional analysis, if you set up right. Fail proof.

nurseprnRN, BSN, RN · Dec 26, 2013

I agree with Miiki dimensional analysis, if you set up right. Fail proof.

And that is precisely my point. "If you set (it) up right" is sometimes more than some people can manage. For the question being posed above, you don't need to do dimensional analysis. You need to do a very simple division problem: How many 500's in 1000? Can't you do that in your head? If not, why not?

I can see that DA is useful in some problems, if (as you say) it is properly applied. But as I mentioned, when people are confused as to what information bits are necessary to solve a particular given problem, slavish devotion to DA can be more trouble than it's worth. You start putting in the 1000, the 500, and the 3 for tid, or the cc's per hour or the total in the bag or whatever, and perhaps the pt's weight, and before you know it you have hash, but you don't have the right answer.

And the people who write the test questions recognize that the aspiring nurse who will be unsafe giving medications will have relied on this formula to give her the answer every time without understanding where it comes from, and they will put in wrong answer choices to trip her up, and she will choose one of the wrong ones because it will match hers...because she used the formula mistakenly, without knowing why.