Need to determine dose based on weight.

[deemarys]

Can someone help me do 1 problem so I can model it for similar problems of this kind. I am not sure what to do. Please step by step.

1. Order: Amoxicillin suspension 40 mg/kg/day in 3 divided doses. Supply: bottle labeled 125 mg/5ml. Childs weight is 15 kg. What is the quantity to administer? _______ml.

Do I do 5/125 = x/600. I got the 600 by multiplying 15kg by 40 mg. ??? I got 24 ml for the day and then divided into 3 doses its 8ml. Is that correct?

Can anyone give me a formula that can help me determine the answer. Thanks in advance to anyone who chooses to help me with this.

D

[RNShenanigator]

Yup that's what I got. Good Job!!!

[serenity1]

I got the same thing-8 ml per dose. The way I would do it is:

15 kg x 40mg = 600 mg

600 mg per dose / 3 doses =200 mg

125 mg:5 ml = 200 mg:X ml--ratio problem-- multiply inside numbers 5x200=1000 divide by remaining number 125 = 8ml

Outside numbers multiplied should equal inside numbers multiplied

Hope I explained it ok. I can show it easier than typing it out. This is how I learned.

[Daytonite, BSN, RN]

Order: Amoxicillin suspension 40 mg/kg/day in 3 divided doses.

Supply: bottle labeled 125 mg/5ml. Childs weight is 15 kg. What is the quantity to administer? _______ml.

By Dimensional Analysis:

40 mg/kg

(dose desired)

x 15 kg

(child's weight)

/3

(number of doses per day)

x 5 mL/125 mg

(dose on hand)

=

8 mL

(amount to administer per dose)