Question

A dose of a drug is 20 mg/kg. The patient weighs 23 kg. Use dimensional analysis to determine how many mg of the drug this patient should receive

Answer 1

460 mg drug is required for the patient whose weight is 23 kg .

Explanation:

It is given that a dose of a drug is 20 mg/kg.

It means for 1 kg weight 20 mg drug is required.

The ratio of drug and weight is

`(drug)/(weight)=(20)/(1)`

The weight of a patient = 23 kg

Let x mg drug is required for the patient whose weight is 23 kg. The ratio of drug and weight is

`(drug)/(weight)=(x)/(23)`

Equate both ratios.

`(x)/(23)=(20)/(1)`

On cross multiplication we get

`x=20* 23`

`x=460`

Therefore, 460 mg drug is required for the patient whose weight is 23 kg.