Drug Calculations

Question 1

Basic Calculations

Answer 1

Dose = dosage x body weight / drug concentration

Question 2

Percentage Solutions %w/v

Answer 2

• A % weight of solute by volume, measured in grams in 100 millilitres
• Most common

Question 3

Percentage Solutions %w/w

Answer 3

• A % weight of solute by weight, measured in grams in 100 grams

Question 4

Percentage Solutions %v/v

Answer 4

• A % weight of a substance by volume, measured in millilitres in 100 millilitres

Question 5

Solutions as percentages

Answer 5

• Drugs are typically expressed and prescribed as a mass (mg, mL ect) a good starting point is converting the % to a mass
• Multiply the % by 10, it will give the concentration of the drug as mg/ml

Question 6

Glucose Calculation

Answer 6

Desired calculation (mg/ml) x solution volume (ml) / initial concentration