Dosing formulas

Question 1

you want to find a patient’s specific dose for a drug based on their body weight

Answer 1

Patients dose = weight (kg) x the usual dose

Question 2

you want to find a total quantity of drug to be given to a patient based on number and size of dose

Answer 2

total quantity = number of dose x size of dose

you can rearrange to find number of doses and size of doses.

any time they are giving you either total quantity, number or doses, or sizing of doses, use this equation

Question 3

Rate of Flow in an IV (ml)

Answer 3

rate of flow = volume of infusion (ml) x drip set (drops/ml) / time (min)