What is the usual dose of a drug is 5 grains? Solve for the safe dose for…(express your answer in mg) a 5 year old child

Question

Applying:

a) use Young’s Rule

b) use Cowling’s Rule

Answer 1

a) Young's rule:

child's dose = Adult dose x (child's age/child's age + 12)

child's dose = 5 gr x (5 / 5+12) = 5 g x (5 / 17)

child's dose = 5 gr x 0.294

child's dose = 1.47 gr

Converting this to mg, we have...

1.47 gr x 64.8 mg / gr = 95 mg

b) Cowling's rule:

child's dose = Adult dose x (child's age + 1 / 24)

child's dose = 5 gr x (5+1 / 24)

child's dose = 5 g x 6/24

child's dose = 1.25 gr

Converting this to mg, we have...

1.25 gr x 64.8 mg / gr = 81 mg