Dosage Question

*ac* · Dec 11, 2009

A child is receiving 175 mg of a certain medication and the minimal and maximal dilution range is 5 to 75 mg/ml. What is the minimum and maximum volume of fluid for safe dilution?
How do you attempt to solve this question? I know I am missing something here.

This is a very strange question. But you would use a theoretical concentration and equate it to the desired dose. So if your concentration is 5mg/1ml, how many ml's do you need to get 175 mg? I would set it up as a ratio problem; 5/1 = 175/x, and solve for x. (175x1)/5.

For the max it would 75/1 = 175/x. (175x1)/75.

Hope this makes sense.

AZMOMO2 · Dec 11, 2009

Not really but thanks for trying!!

Nursey103, ADN, RN · Dec 11, 2009

What is up with all these weird math questions?! I'm lucky they don't throw stuff like this at us in my program.

Usually they'll give you a minimum & maximum dose...for example. Tylenol's min & max dose is like 250 mg to 4000mg. Then you would find out what the supply is (ex. 250mg/5ml) - then you would know what the min & max ml are (ex. 5ml to 80ml). These are just examples of mg & ml.

Is that the actual question you're being given?

If the patient is being given 175mg. Min. concentration would be 5mg/ml & max would be 75mg/ml.

175mg x 1ml / 5mg (dimensional analysis) would give you 35ml (maximum)

175mg x 1ml / 75mg would give you 2.3 ml (minimum)

I think that's what they're asking......doesn't make a whole lot of sense though.

Good luck!! :up:

AmyJean · Dec 12, 2009

You need to know the childs weight in order to calculate the min and max dosage.