Question

If the proper dosage of a drug is 2 mg/kg of body weight, how many milligrams would a 110-lb individual need?

Answer 1

Your patient needs `"100 mg"`.

SInce your drug's dose is expressed in mg per kg, you'll need to convert it to mg per pound first, and then determine how much a 110-lbs patient would need.

`2 "mg"/"kg" * "1 kg"/"2.20462 lbs" = "0.9072 mg/lbs"`

then

`"110 lbs" * 0.9072"mg"/"lbs" = "99.8 mg"`

Rounded to one sig fig, the number of sig figs in 2 mg, the answer will be

`m_("drug") = "100 mg"`

You can do this in one longer step as well

`2 "mg"/"kg" * "1 kg"/"2.20462 lbs" * "110 lbs" = "100 mg"`