A mother calls you to ask about a proper dosage of cough medicine for her 2-year-old. The bottle says to administer 5.0mg/kg three times a day for children under 3 years of age. The cough syrup is supplied in a liquid that contains 50.0mg/mL. How many teaspoons of cough syrup should she give the child, who weighs 34lb , in each dose?

Question

A mother calls you to ask about a proper dosage of cough medicine for her 2-year-old. The bottle says to administer 5.0mg/kg three times a day for children under 3 years of age. The cough syrup is supplied in a liquid that contains 50.0mg/mL.  How many teaspoons of cough syrup should she give the child, who weighs 34lb , in each dose?

matt101 · Answer

First convert pounds to kilograms. At about 0.45 kg/lbs, 34 lbs = 15.4 kg.

Now we need to figure out how much cough syrup the child needs. 5.0 mg/kg x 15.4 kg = 77 mg of cough syrup.

Next we need to find the volume of liquid that contains 77 mg of cough syrup. 77 mg / 50 mg/mL = 1.54 mL

A teaspoon is 5 mL in volume, so the child should be given 1.54/5 = 0.3 tsp of medicine per dose.

Side note...this seems like an awfully small volume to give - are your numbers in the question right? If anything doesn't make sense please ask!

anonymous · Answer

Thanks for your reply...the numbers are straight from the textbook and the correct answer turned out to be .31
I was unsure how to set these type of problems up, but I see I need to convert first. Thanks for the help!