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DOH Pharmacology & Dosage Calculations Practice Questions
Pharmacology is one of the largest parts of every Gulf nursing exam. Expect high-alert drugs, antidotes, side effects to report and dosage calculations. Below are 5 free sample questions for the DOH Registered Nurse exam, each with the answer and a rationale.
What this topic covers
- Dosage and IV drip-rate calculations
- Anticoagulants and their antidotes
- Insulin and oral hypoglycaemics
- Digoxin, diuretics and potassium
- Opioids, naloxone and paracetamol toxicity
- Antibiotics, lithium and high-alert medicines
The full bank has 150 pharmacology & dosage calculations questions, part of 1,500 questions across 16 nursing topics.
Free DOH pharmacology & dosage calculations questions
1. A patient is prescribed oral furosemide once daily. When is the best time to take it?
- A. In the morning
- B. At bedtime
- C. In the middle of the night
- D. Just before the evening meal
Show answer and rationale
Taking a diuretic in the morning prevents nocturia and disturbed sleep.
Reference: Standard nursing pharmacology – diuretics
2. In an emergency a nurse accepts a verbal medication order from a prescriber. What should the nurse do?
- A. Ask another nurse to listen and give the drug without writing it down
- B. Give the drug and ask the prescriber to write it later without repeating it
- C. Write it down and read the whole order back to the prescriber for confirmation
- D. Remember the order and document it at the end of the shift
Show answer and rationale
Writing down and reading back verbal orders reduces communication errors; the prescriber then confirms and signs the order as soon as possible.
Reference: Standard patient safety practice – verbal orders and read-back
3. An insulin infusion is prepared as 100 units of regular insulin in 100 mL of 0.9% sodium chloride. The prescription is 6 units/hour. What rate should the pump be set at?
- A. 6 mL/h
- B. 0.6 mL/h
- C. 12 mL/h
- D. 60 mL/h
Show answer and rationale
Concentration = 100 units ÷ 100 mL = 1 unit/mL, so 6 units/h = 6 mL/h.
Reference: Standard dosage calculation – insulin infusion
4. A child is prescribed paracetamol 180 mg orally. The oral suspension available is 120 mg/5 mL. What volume should the nurse give?
- A. 9 mL
- B. 7.5 mL
- C. 5 mL
- D. 6 mL
Show answer and rationale
(Dose required ÷ dose available) × volume = (180 mg ÷ 120 mg) × 5 mL = 1.5 × 5 mL = 7.5 mL.
Reference: Standard dosage calculation – oral liquids
5. A noradrenaline (norepinephrine) infusion contains 4 mg in 250 mL and is running at 15 mL/h. What dose is the patient receiving in micrograms per minute?
- A. 16 micrograms/min
- B. 4 micrograms/min
- C. 0.24 micrograms/min
- D. 40 micrograms/min
Show answer and rationale
Concentration = 4000 micrograms ÷ 250 mL = 16 micrograms/mL. 15 mL/h × 16 = 240 micrograms/h; 240 ÷ 60 = 4 micrograms/min.
Reference: Standard nursing calculations – infusion dose from rate
Study tip
Practise calculations until they are automatic. Write the formula down and check the answer is sensible before you choose.
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