Calculating Drug Doses

Question 1

Provide the symbol and multiplication factor for each scientific prefix: kilo, milli, micro, nano, pico

Answer 1

kilo - K, x 1000
milli - m, 0.0001
micro - μ, 0.0000001
nano - n, 0.0000000001
pica- p, 0.0000000000001

Question 2

Provide the equivalent in mL for each measurement: 1 tsp, 1 tbsp, 1 ounce, 1 cup

Answer 2

1 tsp = 5 mL
1 tbsp = 15 mL (3 tsp)
1 ounce = 30 mL
1 cup = 240 mL (8 ounces)

Question 3

What is the formula for calculating dose using proportions?

Answer 3

original dose/per amount = desired dose/per amount

Question 4

What does ‘dose’ usually refer to? What does ‘per amount’ refer to?

Answer 4

‘dose’ - refers to mass or units of drug

‘per amount’ - quantity of given form of drug, volume of an elixir/suspension

Question 5

What are the 3 types of percentage preparations?

Answer 5

weight to weight, weight to volume, volume to volume

Question 6

Describe weight to weight percentage preparations.

Answer 6

ratio of the weight of the active drug to the total weight of the mixture (active drug and inactive non-drug ingredients)

Question 7

Describe weight to volume percentage preparations.

Answer 7

ratio of the weight of the active drug to the total volume of the mixture

Question 8

Describe volume to volume percentage preparations.

Answer 8

ratio of the volume of the active drug to the total volume of the mixture

Question 9

When mixing solutions, we first add the amount of ______ __________, we then add enough _______ to ‘make up’ the solution to a certain volume

Answer 9

active ingredient, solvent

Question 10

With diluents and drug doses used in nebulizers, the amount of diluent affects what?

Answer 10

amount of time required to administer the drug; amount of active drug is the same

Question 11

What are the 2 types of solutions by ratio?

Answer 11

ratio given in g/mL (W/V) and ratio by simple parts

Question 12

What is the formula(s) for solving percentage-strength solution problems? (3)

Answer 12

% strength = solute/total amount

end decimal form, solute is in grams (mass) or cubic cm (vol), total amount = solute + solvent

OR

amount of solute/total amount = amount of solute/100 parts

OR

desired % strength = (volume of dilute solution x % strength of solute)/total amount (new solution)