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OMSB 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 OMSB nursing 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 OMSB pharmacology & dosage calculations questions
1. Which agent is the specific reversal agent for dabigatran?
- A. Idarucizumab
- B. Vitamin K
- C. Desmopressin
- D. Protamine sulfate
Show answer and rationale
Idarucizumab is a monoclonal antibody fragment that binds and reverses dabigatran.
Reference: Standard nursing pharmacology – direct oral anticoagulants
2. What is the main purpose of the Z-track technique for intramuscular injections?
- A. To prevent medication leaking back into the subcutaneous tissue
- B. To allow a larger volume to be injected into the deltoid
- C. To reduce the pain of needle insertion
- D. To speed up absorption of the drug
Show answer and rationale
Displacing the skin before injection creates a zig-zag track that seals the medication in the muscle, preventing leakage and skin staining (for example with iron preparations).
Reference: Potter & Perry Fundamentals – Z-track injection
3. A patient is prescribed doxycycline. Which instruction should the nurse give?
- A. Take it with antacids to reduce heartburn
- B. Avoid taking it at the same time as dairy products, antacids or iron, and protect the skin from the sun
- C. Take it with a glass of milk to protect the stomach
- D. Take it at bedtime lying down
Show answer and rationale
Calcium, magnesium, aluminium and iron bind tetracyclines and reduce absorption; tetracyclines also cause photosensitivity. They should be taken upright with water to prevent oesophageal irritation.
Reference: Standard nursing pharmacology – tetracyclines
4. Before giving digoxin to an adult, the nurse counts an apical pulse of 54 beats/min. What should the nurse do?
- A. Give half the dose
- B. Give the dose and recheck the pulse in one hour
- C. Withhold the dose and notify the prescriber
- D. Check the radial pulse and give the dose if it is above 60
Show answer and rationale
Digoxin slows the heart rate; it is usually withheld for an adult apical rate below 60 beats/min and the prescriber informed. The apical pulse is counted for a full minute and is more accurate than the radial.
Reference: Standard nursing pharmacology – digoxin
5. A child weighing 15 kg is prescribed an antibiotic at 40 mg/kg/day given in divided doses every 6 hours. How much should be given per dose?
- A. 200 mg
- B. 150 mg
- C. 600 mg
- D. 100 mg
Show answer and rationale
Daily dose = 40 mg/kg × 15 kg = 600 mg. Every 6 hours = 4 doses per day, so 600 mg ÷ 4 = 150 mg per dose. 600 mg is the total daily dose.
Reference: Standard dosage calculation – weight-based dosing
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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