2- Calculating drug doses

Question 1

Define percentage (w/v) solution

Answer 1

A 1% w/v solution is: 1g (of powder) dissolved in 100 ml.
= 10 mg/ml

Question 2

How to calculate dilutions

Answer 2

1. Work out the factor (DF) by which the stock is greater then the final solution
2. The volume required is the total volume (that is going to be administered) divided by the DF
3. Volume of diluent needed is the total volume minus volume of stock drug

Question 3

Why is allometric scaling sometimes used to calculate drug doses

Answer 3

As function of organs responsible for detoxification (i.e. kidney/liver) are more closely related to surface area than body weight