Not sure how to do this. Have tried multiple times

Question

A patient is to receive Amoxil 250mg po every 8 hours. Amoxil is avaliable in a 150mL bottle with a concntration of 250mg/5mL. This bottle will provide how many doses and will last how many days?

Answer 1

How did you approach this problem? I would do something like that: one dose is 5 ml. We have 150 ml bottle. That means that there are 150/5=30 doses in a bottle. We need 3 doses a day (24/8=3).We have 30 doses, 3 a day, 30/3=10. We are good for 10 days.

 

Not sure if I can tie proportions to that.

 

 

Answer 2

First, find how many mg are in one bottle.  A bottle  of volume V = 150 mL has a concentration of

 

C = (250 mg) / (5 mL)

 

Then the number of milligrams M per bottle is:

 

M = C*V = [250 mg / (5 mL)] * (150 ml) = 7500 mg

 

Since the patient consumes 250 mg every 8 hours, then each day (24 hours) he receives

 

d = 3(250 mg) / day = 750 mg/day

 

That is his daily consumption.  Now divide the total available mg by the daily consumption to get the number of days N that the bottle will last:

 

N = M / d = (7500 mg) / (750 mg / day) = 10 days

 

So the bottle lasts 10 days.  At 3 doses per day, that becomes 30 doses.

Answer 3

We need to find out how many mg are in the 150mL bottle. With the concentration given of 250mg/5mL, which is reduced to 50mg/mL. If you have a bottle that is 150mL we would just need to multiply this by 50mg/mL which is 750mg. This will provide three doses and only last 1 day.