How To Do Dosage Conversions?

The recommended adult dose of elixophyllin, a drug used to treat asthma, is 6.0 mg per kg of body weight. Calculate the dose, in milligrams, for a 170 pound person. (1 kg = 2.20462 lbs)

We must start with a 170lbs and then use the ratios given to get to the correct units. The idea is that we want to cross of units we do not want (those will go in the denominator) and get the units we want (go in the numerator).

Therefore we can write this out: 170 lbs * ( 1kg/2.20462 lbs) * (6.0mg/ 1kg)= 460mg