Saudi Prometric Nursing Pharmacology and Drug Calculations 4 — Questions and Answers
Question 1: A child weighing 20 kg is prescribed paracetamol (acetaminophen) 15 mg/kg PO q6h. The available suspension is 250 mg/5 mL. What volume should be given per dose?
- 6 mL (Correct answer)
- 3 mL
- 12 mL
- 5 mL
Correct answer: 6 mL
Dose = 15 mg/kg × 20 kg = 300 mg per dose. Volume = (300 mg / 250 mg) × 5 mL = 1.2 × 5 = 6 mL. Pediatric paracetamol dosing is weight-based; exceeding maximum doses causes hepatotoxicity.
Question 2: Which class of drugs is contraindicated in patients with bilateral renal artery stenosis?
- ACE inhibitors and ARBs (Correct answer)
- Beta-blockers
- Calcium channel blockers
- Thiazide diuretics
Correct answer: ACE inhibitors and ARBs
ACE inhibitors and ARBs reduce glomerular filtration pressure by dilating the efferent arteriole. In bilateral renal artery stenosis, where perfusion pressure is maintained by angiotensin II, this effect causes acute renal failure. These drugs are contraindicated in this condition.
Question 3: The nurse is preparing to give IV morphine for severe pain. Which side effect must the nurse have equipment ready to manage?
- Respiratory depression — have naloxone (Narcan) at bedside (Correct answer)
- Hypertension — have antihypertensives ready
- Tachycardia — have beta-blockers available
- Hyperglycemia — have insulin available
Correct answer: Respiratory depression — have naloxone (Narcan) at bedside
The most dangerous side effect of opioids is respiratory depression, which can be fatal. Naloxone (Narcan) is the opioid antagonist used to reverse respiratory depression. Resuscitation equipment should also be available when administering IV opioids.
Question 4: A patient on long-term corticosteroid therapy is at risk for which electrolyte imbalance?
- Hypokalemia and hypernatremia (Correct answer)
- Hyperkalemia and hyponatremia
- Hypocalcemia and hypomagnesemia
- Hyperphosphatemia and hypercalcemia
Correct answer: Hypokalemia and hypernatremia
Corticosteroids have mineralocorticoid effects causing sodium and water retention (hypernatremia) and potassium excretion (hypokalemia). They also impair calcium absorption and promote bone resorption. Long-term use requires monitoring of potassium, sodium, blood glucose, and bone density.
Question 5: The nurse is administering IV calcium gluconate. What medication must be available at the bedside as an antidote?
- Sodium bicarbonate and cardiac monitoring equipment (Correct answer)
- Calcium EDTA
- Protamine sulfate
- Flumazenil
Correct answer: Sodium bicarbonate and cardiac monitoring equipment
Calcium gluconate is used to treat hypocalcemia and to protect the heart in hyperkalemia. However, rapid administration can cause bradycardia and cardiac arrest. ECG monitoring and resuscitation equipment (including sodium bicarbonate to manage arrhythmias) should be available.
Question 6: The order reads: 'IV fluids at 125 mL/hr.' Using a standard drip set (20 drops/mL), what is the drip rate in dpm?
- 42 dpm (Correct answer)
- 125 dpm
- 25 dpm
- 60 dpm
Correct answer: 42 dpm
Drip rate = (mL/hr × drop factor) / 60 = (125 × 20) / 60 = 2,500 / 60 = 41.67 ≈ 42 dpm. A simpler approach: for 20 gtt/mL sets, divide mL/hr by 3. 125/3 ≈ 42 dpm.
Saudi Prometric Nursing Pharmacology and Drug Calculations 4
A child weighing 20 kg is prescribed paracetamol (acetaminophen) 15 mg/kg PO q6h.
The available suspension is 250 mg/5 mL.
What volume should be given per dose?