This is a practice question from the PTCE

Question

A family is sick and is prescribed amoxicillin with individual doses based on weight in the following formula: 40mg/kg/day in divided doses Q8h. The amoxicillin available in the pharmacy is 250mg/5mL. How much amoxicillin would a 28lb child take in mL over a 7 day course of treatment?

Answer 1

Given :

1. Dosage : 40mg/kg/day
2. Child's weight = 28lb = 12.7kg
3. Duration of therapy = 7 days
4. Available strength = 250mg/5ml

To find:

Amount of amoxicillin required over the duration of therapy in volume (mL)?

Total daily dose required : 40 mg x 12.7 kg = 509mg

Over a 7 day period, amount in mg required = 509mg x 7 days = 3563mg

If strength available is 250mg in 5ml

then 3563mg = ? mL

3563 mg x 5 mL/250 mg = 71.26mL or 72 mL approximately