drug calulation questions

[bltfam]

Hi I have a dosage cal question and i keep getting the same answer

not sure what i am doing wrong I'm usually pretty good with these but this one i am lost. It will be the only one i get wrong but now its becone a battle If any one can answer please do

DR orders PCN V K plus oral suspenion 56mg/kg/dayin 4 divided doses for a child weighing 55 pounds The suspension aval is 125/5ml whats the vol for each dose

i keep getting 7 ml

thanx

[loricatus]

I quickly calculated 14 mL. Is that the answer you are supposed to be getting?

[bltfam]

yes i think

can you tell me how you got that number

[loricatus]

I'll try.

55lbs divided by 2.2 = 25 kg [lbs. to kg conversion]

25 * 56 = 1400 mg /day needed [kg x mg/day]

1400/4= 350 mg per dose [4 divided doses per day]

Cross multiply:

125mg / 5mL = 350mg / X ml

350 * 5 = 1750

125x

x=1750/125

x= 14 mL

It's basically saying that if you have 125 mg per each 5 mL, you will need 14 mL to make a 350 mg dosage.

[bltfam]

thanx

i see what i was doing now instead of 1400 divided by 4to get 350

didnt add the extra 0 on and was calulating it with 140 which made it 7

I just thiught i was going crazy

thanx again

[angel Ann]

Order: 56 mg/kg/day X 4 divided doses

child weight 55 lbs = 25 kg

Stock: 125 mg/5ml

My answer:

56 (mg) X 25 (kg) = 1400 mg/ day

1400/4 = 350 mg QID

D/S X Q =

350 mg/125 mg X 5ml = 14 mls.

Im not sure how old is a 25 kg child but normally for 6-12 yrs old, dose is usually 250 mg every 6 hours which is 4x/day or 1gm/day

[Daytonite, BSN, RN]

Doctor orders PCN V K Plus oral suspension 56mg/kg/day in 4 divided doses for a child weighing 55 pounds. The suspension available is 125mg per 5ml. What is the volume of each dose?

By dimensional analysis:

56 mg/1 kg

(dose desired)

x 5 mL/125 mg

(dose on hand)

x 55 pounds

(weight of child)

x 1 kg/2.2 pounds

(conversion factor) =

56 mL (per day)

Since the daily dose is to be divided into 4 doses, then

56 mL

divided by

4 =

14 mL per dose

[SarasotaRN2b]

I'll try.

55lbs divided by 2.2 = 25 kg [lbs. to kg conversion]

25 * 56 = 1400 mg /day needed [kg x mg/day]

1400/4= 350 mg per dose [4 divided doses per day]

Cross multiply:

125mg / 5mL = 350mg / X ml

350 * 5 = 1750

125x

x=1750/125

x= 14 mL

It's basically saying that if you have 125 mg per each 5 mL, you will need 14 mL to make a 350 mg dosage.

YEP, that is what I got!

[Joni's Mom]

Dimensional Analysis

Start with what you want.

ml = 5ml x 56mg x Kg x 55 lb = 15400 = 14ml

Dose 125mg Kg 2.2 lb 4 doses 1100 Dose