PSI Pharmaceutical Calculations 3

Question 1

A drug has a half-life of 6 hours. What fraction of the original dose remains in the body after 24 hours?

Accepted Answer

1/16

Answer

1/4

Answer

1/8

Answer

1/12

Question 2

A patient has a creatinine clearance of 30 mL/min (normal = 100 mL/min). A renally cleared drug is normally dosed every 8 hours. What is the appropriate adjusted dosing interval?

Accepted Answer

Approximately every 27 hours

Answer

Every 8 hours

Answer

Every 12 hours

Answer

Every 48 hours

Question 3

An aminoglycoside is to be dosed to achieve a peak concentration of 8 mg/L. The patient weighs 60 kg and the volume of distribution is 0.25 L/kg. What loading dose is required?

Accepted Answer

120 mg

Answer

30 mg

Answer

60 mg

Answer

480 mg

Question 4

A 500 mL bag of 5% dextrose for infusion contains how many grams of dextrose?

Accepted Answer

25 g

Answer

5 g

Answer

10 g

Answer

50 g

Question 5

A topical preparation contains a drug at 0.1% w/v. How many milligrams of drug are present in 20 mL of the preparation?

Accepted Answer

20 mg

Answer

0.2 mg

Answer

2 mg

Answer

200 mg

Question 6

A pharmacist mixes 300 mL of a 6% solution with 200 mL of a 1% solution of the same drug. What is the final percentage concentration?

Accepted Answer

4.0%

Answer

3.0%

Answer

3.5%

Answer

5.5%

Question 7

Insulin is available as 100 units/mL in 10 mL vials. A patient requires 30 units twice daily for 28 days. How many vials must be dispensed?

Accepted Answer

2 vials

Answer

1 vial

Answer

3 vials

Answer

4 vials