Q1. The dry cough caused by ACE inhibitors is due to: A. Direct irritation of the airway B. Accumulation of BRADYKININ C. Excess angiotensin II D. Potassium retention ANSWER: B — bradykinin accumulation. Why: ACE also degrades bradykinin, so inhibiting it allows bradykinin to accumulate. ARBs block the receptor instead and therefore do not cause cough. LEARNING POINT: this is why switching from an ACE inhibitor to an ARB abolishes the cough.

Q2. Which diuretic class RETAINS potassium? A. Loop diuretics B. Thiazides C. ALDOSTERONE ANTAGONISTS D. All diuretics lose potassium ANSWER: C — aldosterone antagonists. Why: they act at the collecting duct to block aldosterone, so sodium is lost and potassium retained. Loop and thiazide diuretics do the opposite. LEARNING POINT: spironolactone plus an ACE inhibitor is a recognised cause of hyperkalaemia.

Q3. An 80-year-old stable on digoxin is started on a loop diuretic. Two weeks later she is confused, nauseated, bradycardic and reports yellow-tinged vision. The cause is: A. Stroke B. DIGOXIN TOXICITY precipitated by hypokalaemia C. Diuretic allergy D. Dementia ANSWER: B. Why: hypokalaemia potentiates digoxin at the sodium-potassium pump, so a previously safe dose becomes toxic. Visual disturbance with a yellow-green tinge is characteristic. LEARNING POINT: the dose did not change — the patient did.

Q4. A 72-year-old with atrial fibrillation, hypertension and diabetes needs stroke prevention. The appropriate therapy is: A. Aspirin B. ANTICOAGULATION after formal risk assessment C. Clopidogrel D. No treatment ANSWER: B — anticoagulation. Why: the clot forms in a stagnant fibrillating atrium and is fibrin-rich, behaving like a venous thrombus. Antiplatelet therapy is inadequate stroke prevention in AF. LEARNING POINT: assess stroke and bleeding risk formally rather than substituting a weaker drug for the concern.

Q5. A man on an ACE inhibitor and a diuretic takes an NSAID, then develops vomiting and diarrhoea. He presents with acute kidney injury and hyperkalaemia. The mechanism is: A. Direct nephrotoxicity of the diuretic alone B. Afferent constriction by the NSAID, efferent dilatation by the ACE inhibitor, and volume depletion C. An allergic reaction D. Urinary obstruction ANSWER: B. Why: glomerular filtration depends on the pressure gradient across the afferent and efferent arterioles. Constricting one, dilating the other, and reducing circulating volume together cause filtration to collapse. LEARNING POINT: give sick-day advice about pausing these drugs during dehydrating illness.

Q6. A patient develops ankle oedema on amlodipine. The correct action is: A. Add a diuretic B. CHANGE the antihypertensive C. Restrict fluid intake D. Elevate the legs only ANSWER: B — change the drug. Why: dihydropyridine ankle oedema results from arteriolar dilatation increasing capillary pressure, not from fluid overload. A diuretic therefore does not correct it and risks volume depletion. LEARNING POINT: match the treatment to the mechanism, not to the appearance.

Q7. Why are heparins rather than warfarin used for anticoagulation in pregnancy? A. Heparins are more effective B. Warfarin is TERATOGENIC and crosses the placenta; heparins do not cross C. Warfarin cannot be monitored in pregnancy D. Heparins are cheaper ANSWER: B. Why: warfarin crosses the placenta and is teratogenic. Heparins are large molecules that do not cross, making them the anticoagulants of choice in pregnancy. LEARNING POINT: ACE inhibitors, ARBs, aldosterone antagonists and statins are also avoided in pregnancy.