dosage calculation

Question

The recommended dose for Mintezol 0.01g/kg/day given 3 times a day. It is available as 500mg per 5mL. Child weighs 39 pounds. How many mg can be given per dose? How many mL should be given per dose?

Answer 1

We will use the multiplicative identity (that is, 1) to change the units without changing the value, because we may multiply any value by 1 and not change it.  For example,

             2 yards

            (2 yards)*1

            (2 yards)*(3 feet / 1 yard)

             6 feet              (note: yards cancel out, leaving only feet)

 

This problem gives the allowable dosage:

     ( 0.01g/kg/day )*(39 pounds)          and, first, we want to know mg/dose

     ( 0.01g/kg/day )*(39 lbs)*(1000 mg/g)*(1 kg/(2.2 lb))*(1 day/3 dose) )

     ( 0.01*39*1000/(2.2*3) ) mg/dose             (note how units cancel out !)

      59.09 mg /dose

Mintezol is available as 500 mg per 5 mL, so

      (59.09 mg/dose)*(5 mL / (500 mg) )             (again, multiplicative identity)

        0.59 mL/dose         (note: 1 mL = 1 cc, so this is a little more than 1/2 cc)

 

Answer 2

you have to change your measurements from g and kg to mg and lb

 

1g = 1000ml, so 0.01g x 1000= 10ml

 

1kg = 2.2 lb

 

so we have 10ml/2.2lb 3 times a day that is 30ml/2.2lb/day

 

so for 39lb is 39x 10ml/2.2 = 390ml/22= 17.7 ml or 18 ml/day or 6ml 3x/day