APC Pharmaceutical Calculations

Question 1

A patient requires 250 mg of amoxicillin. The oral suspension is labeled 125 mg/5 mL. How many mL should be given per dose?

Accepted Answer

10 mL

Answer

Using ratio-proportion: (250 mg ÷ 125 mg) × 5 mL = 10 mL per dose.

Question 2

A prescription calls for 2.5% w/w hydrocortisone cream. How many grams of hydrocortisone are contained in a 100 g tube?

Accepted Answer

2.5 g

Answer

A 2.5% w/w preparation contains 2.5 g of solute per 100 g of product.

Question 3

A 60 kg patient requires 5 mg/kg/day of tobramycin. What is the total daily dose?

Accepted Answer

300 mg

Answer

Total dose = 60 kg × 5 mg/kg = 300 mg/day.

Question 4

A 1 in 1000 solution of epinephrine contains how many milligrams per milliliter?

Accepted Answer

1 mg/mL

Answer

1 in 1000 means 1 g per 1000 mL, which equals 1 mg per mL.

Question 5

You need to prepare 200 mL of a 2% solution from a 10% stock solution. How many mL of the stock solution are required?

Accepted Answer

40 mL

Answer

Using C1V1 = C2V2: 10% × V1 = 2% × 200 mL, so V1 = 40 mL.

(APC) Australian Pharmacy Council Practice Test