PSI Pharmacology & Therapeutics

Question 1

Which class of antihypertensives is the first-line treatment in patients with heart failure with reduced ejection fraction (HFrEF)?

Accepted Answer

ACE inhibitors

Answer

ACE inhibitors (e.g., ramipril, lisinopril) reduce mortality and morbidity in HFrEF by blocking angiotensin II production, reducing cardiac afterload and preload.

Question 2

Aspirin's antiplatelet effect is due to irreversible inhibition of which enzyme?

Accepted Answer

COX-1 (cyclooxygenase-1)

Answer

Aspirin irreversibly acetylates COX-1 in platelets, blocking thromboxane A2 synthesis. Because platelets lack nuclei, they cannot regenerate COX-1, so the effect lasts the platelet's 7–10 day lifespan.

Question 3

Which opioid is considered a partial agonist at the mu-opioid receptor?

Accepted Answer

Buprenorphine

Answer

Buprenorphine is a partial agonist at the mu-opioid receptor with high receptor affinity. Its ceiling effect on respiratory depression makes it safer in overdose than full agonists.

Question 4

The main mechanism of action of metformin in type 2 diabetes is:

Accepted Answer

Reduction of hepatic glucose output

Answer

Metformin primarily activates AMPK, reducing hepatic gluconeogenesis and glycogenolysis, thereby decreasing fasting blood glucose. It does not cause hypoglycaemia alone.

Question 5

Which beta-blocker is cardioselective (beta-1 selective) at normal doses?

Accepted Answer

Bisoprolol

Answer

Bisoprolol (and atenolol, metoprolol) selectively block beta-1 adrenergic receptors at therapeutic doses, minimising bronchospasm risk compared to non-selective beta-blockers.

PSI Pharmacy Practice Test

PSI Pharmacy Practice Test

PSI Pharmacology & Therapeutics