CETP Pharmaceutical Calculations

Question 1

A patient is prescribed amoxicillin 250 mg/5 mL oral suspension. The prescribed dose is 125 mg three times daily. How many mL should be administered per dose?

Accepted Answer

2.5 mL

Answer

125 mg ÷ (250 mg/5 mL) = 125 ÷ 50 mg/mL = 2.5 mL per dose.

Question 2

A physician orders 1 L of normal saline to be infused over 8 hours. What is the correct infusion rate in mL/hr?

Accepted Answer

125 mL/hr

Answer

1000 mL ÷ 8 hours = 125 mL/hr.

Question 3

What is the percentage strength (w/v) of a solution containing 5 g of sodium chloride dissolved in enough water to make 200 mL?

Accepted Answer

2.5%

Answer

Percentage w/v = (5 g ÷ 200 mL) × 100 = 2.5%.

Question 4

A child weighs 22 lbs. The prescribed antibiotic dose is 10 mg/kg/day in two equally divided doses. How many mg should be given per dose?

Accepted Answer

50 mg

Answer

22 lbs ÷ 2.2 = 10 kg; 10 kg × 10 mg/kg/day = 100 mg/day ÷ 2 doses = 50 mg per dose.

Question 5

How many grams of dextrose are contained in 500 mL of D5W (5% dextrose in water)?

Accepted Answer

25 g

Answer

5% w/v = 5 g per 100 mL; 500 mL × 5 g/100 mL = 25 g of dextrose.

Canadian Entry To Practice

Canadian Entry To Practice

CETP Pharmaceutical Calculations