Question

Order: Amikacin sulpate 35 mg/kg daily, maximum  dose of 15mg/kg/day in 3 divided doses every 8 hours

Available: Amikacin sulphate 250 mg/ml

Child weights 77 pounds

How many milligrams will the nurse administer?

How many milliliters are in each dose?

Will the medication be administered in a 1ml syringe, 3-ml syringe, 5-ml syringe or 10ml syringe? Explain your answer

Answer 1

Maximum dose of Amikacin = 15 mg/kg/day in 3 divided doses given every 8 hourly ------- (1)

Amikacin sulphate available - 250 mg/ml------- (2)

Weight of the child = 77 pounds

weight of the child in kgs =

• 1kgs = 2.2 pounds
• Therefore 'x' kgs = 77 pounds
• Therefore x = 77 / 2.2 = 35 kgs

Answer 1: let us calculate the dose for this child ( weighing 77 pounds = 35 kgs)

as per the statement (1), the recommended dose for per day in mg is

• 15 mg/ kg /day
• Therefore, for a child weighing 35 kgs the dose is
• 15 * 35 = 525 mg/day
• Therefore 525 mg of amikacin has to be given in 1 day.
• But this has to infused into the patient in 3 divided doses
• , therefore, = 525 / 3 = 175 mg per dose 3 times a day.------ (3)

Amikacin is available in the dose of 250 mg/ ml

• therefore 1 ml of medicine contain = 250 mg of amikacin ---( 4)
• However, from statement 3,  we are supposed to give 175 mg of amikacin 3 times a day.
• Therefore 'y' ml of medicine will provide 175 mg of amikacin.--- (5)
• Therefore, by cross multiplication y ml = 175 mg * 1 ml / 25o ml
• mg above gets cancelled = y = 175 * 1 ml / 250
• = y = 175 ml / 250 = 0.7 ml
• Therefore 0.7 ml of amikacin should be administered with each dose ( this will provide 175 mg of amikacin)

Another way of solving this problem

• from statement (2) = 1 ml = 250 mg
• Thereofore 1 mg = 1 ml /250 mg ( just rearranging the question)
• So 175 mg = 1 ml /250 mg * 175 mg = 0.7 ml (mg gets cancelled)

The synringe to be used is = 1 ml

• explanation = the 1 ml syringe is has 1 / 100 ml graduations.
• In other words = every short black line on the syringe is 0.01 ml and every long line appears after 10 short lines = 10 * 0.01= 0.1 ml.
• The 7 th long line from the needle on the syringe corresponds to 0.7 ml ( it is printed on the syringe's barrel)
• The nurse has to withdraw the medicine up to this 0.7 mark to aspirate 0.7 ml of amikacin for every dose.

Final statement -

1. This child needs 525 mg of amikacin / day
2. This will be administered to the patient 175 mg 3 times a day every 8 hourly.
3. The nurse has to give 0.7 ml of the medicine every 8 hourly to administer a dose of 175mg
4. The nurse need to use a 1 ml syringe.