Saudi Prometric Nursing Pharmacology and Drug Calculations 3 — Questions and Answers
Question 1: The nurse is preparing to administer insulin. The order reads: 'Regular insulin 10 units IV push.' The available vial is U-100 insulin. How many mL should be drawn up?
- 0.1 mL (Correct answer)
- 1 mL
- 0.5 mL
- 0.01 mL
Correct answer: 0.1 mL
U-100 insulin contains 100 units per mL. Volume = 10 units ÷ 100 units/mL = 0.1 mL. This small volume requires use of an insulin syringe for accuracy. Note: only regular insulin is used IV; NPH and long-acting insulins are not for IV use.
Question 2: Which of the following antibiotics requires dose adjustment in patients with renal impairment?
- Gentamicin (Correct answer)
- Azithromycin
- Clindamycin
- Metronidazole
Correct answer: Gentamicin
Gentamicin (an aminoglycoside) is renally excreted and accumulates in renal impairment, increasing the risk of nephrotoxicity and ototoxicity. Azithromycin, clindamycin, and metronidazole are primarily hepatically metabolized and generally do not require renal dose adjustment.
Question 3: A nurse is preparing an IV infusion of nitroglycerin. Which type of IV tubing must be used?
- Non-PVC, non-DEHP tubing (special nitroglycerin tubing) (Correct answer)
- Standard PVC IV tubing
- Filtered IV tubing
- Microbore IV tubing
Correct answer: Non-PVC, non-DEHP tubing (special nitroglycerin tubing)
Nitroglycerin is absorbed by PVC (polyvinyl chloride) IV tubing and bags, significantly reducing the delivered dose. Special non-PVC, non-DEHP tubing must be used to ensure the patient receives the full prescribed dose. This is a critical nursing safety point.
Question 4: The nurse is teaching a patient about taking oral iron supplements. Which instruction maximizes iron absorption?
- Take on an empty stomach or with vitamin C (orange juice) (Correct answer)
- Take with milk to reduce GI upset
- Take with antacids if stomach discomfort occurs
- Take with a high-fiber meal to maximize absorption
Correct answer: Take on an empty stomach or with vitamin C (orange juice)
Iron absorption is maximized in an acidic environment and is enhanced by vitamin C (ascorbic acid). Milk, calcium, antacids, and high-fiber foods reduce iron absorption. Taking iron with vitamin C can increase absorption by 2–3 times.
Question 5: A patient is prescribed metoprolol. What is the most important assessment before administering a beta-blocker?
- Heart rate and blood pressure (Correct answer)
- Respiratory rate and oxygen saturation
- Blood glucose level
- Serum potassium level
Correct answer: Heart rate and blood pressure
Before administering any beta-blocker, the nurse must assess heart rate and blood pressure. Beta-blockers slow heart rate and reduce blood pressure. They should be withheld if HR <60 bpm or systolic BP <90 mmHg (per institutional parameters or physician orders).
Question 6: A patient is taking St. John's Wort with their antiretroviral therapy. What is the most significant drug interaction concern?
- St. John's Wort induces CYP3A4 and reduces antiretroviral drug levels, risking treatment failure (Correct answer)
- St. John's Wort enhances antiretroviral absorption
- St. John's Wort causes serotonin syndrome with antiretrovirals
- No significant interaction exists
Correct answer: St. John's Wort induces CYP3A4 and reduces antiretroviral drug levels, risking treatment failure
St. John's Wort is a potent CYP3A4 inducer, significantly increasing the metabolism and clearance of many antiretroviral drugs (protease inhibitors, NNRTIs). This reduces drug levels below therapeutic range, causing treatment failure and potential development of HIV drug resistance.
Saudi Prometric Nursing Pharmacology and Drug Calculations 3
The nurse is preparing to administer insulin.
The order reads: 'Regular insulin 10 units IV push.' The available vial is U-100 insulin.
How many mL should be drawn up?