DHA Pharmacist Clinical Pharmacology

Question 1

A patient taking simvastatin is prescribed clarithromycin for a respiratory infection. What is the primary concern?

Accepted Answer

Clarithromycin inhibits CYP3A4, dramatically increasing simvastatin levels and the risk of myopathy/rhabdomyolysis

Answer

No clinically significant interaction exists

Answer

The combination reduces the efficacy of clarithromycin

Answer

Simvastatin increases clarithromycin levels

Question 2

Which receptor type mediates the bronchodilator effect of salbutamol (albuterol)?

Accepted Answer

Beta-2 adrenergic receptors in bronchial smooth muscle

Answer

Alpha-1 adrenergic receptors

Answer

Muscarinic M3 receptors

Answer

H1 histamine receptors

Question 3

What is the mechanism of action of metformin in type 2 diabetes?

Accepted Answer

Activates AMPK to reduce hepatic glucose production and improve insulin sensitivity

Answer

Stimulates pancreatic beta cells to secrete more insulin

Answer

Blocks alpha-glucosidase to delay carbohydrate absorption

Answer

Inhibits SGLT-2 to increase urinary glucose excretion

Question 4

Which adverse effect is uniquely associated with ACE inhibitors and distinguishes them from ARBs?

Accepted Answer

Dry, persistent cough caused by bradykinin accumulation

Answer

Hyperkalaemia

Answer

Angioedema (also seen with ARBs but much less commonly)

Answer

Hypotension on first dose

Question 5

What is the pharmacological basis for using atropine to treat bradycardia?

Accepted Answer

Atropine blocks muscarinic receptors, preventing acetylcholine-induced slowing of the heart rate

Answer

Atropine stimulates beta-1 receptors directly

Answer

Atropine releases norepinephrine from nerve terminals

Answer

Atropine blocks potassium channels in the SA node

Question 6

Which enzyme does aspirin irreversibly inhibit to achieve its antiplatelet effect?

Accepted Answer

Cyclooxygenase (COX-1)

Answer

Phospholipase A2

Answer

Thrombin

Answer

Factor Xa