PSI Pharmacology & Therapeutics 4

Question 1

Which drug is used to reverse opioid overdose?

Accepted Answer

Naloxone

Answer

Naloxone is a competitive opioid receptor antagonist with high affinity for mu-receptors. IV/IM/intranasal naloxone rapidly reverses respiratory depression, sedation and miosis of opioid overdose.

Question 2

Proton pump inhibitors (PPIs) like omeprazole work by:

Accepted Answer

Irreversibly inhibiting H+/K+ ATPase in gastric parietal cells

Answer

PPIs are prodrugs activated in the acidic canaliculi of parietal cells. Active drug covalently binds and irreversibly inhibits H+/K+ ATPase (the proton pump), suppressing acid secretion.

Question 3

Which antibiotic class acts by inhibiting bacterial protein synthesis at the 30S ribosomal subunit?

Accepted Answer

Aminoglycosides

Answer

Aminoglycosides (e.g., gentamicin) bind the 30S ribosomal subunit, causing misreading of mRNA and production of aberrant proteins, leading to bacterial cell death.

Question 4

Calcium gluconate is urgently required in hyperkalaemia to:

Accepted Answer

Stabilise cardiac membrane potential

Answer

Calcium gluconate rapidly antagonises the effect of high potassium on cardiac membrane excitability, preventing arrhythmias. It works within minutes but does not lower potassium.

Question 5

Which drug is a direct oral anticoagulant (DOAC) that inhibits thrombin (factor IIa)?

Accepted Answer

Dabigatran

Answer

Dabigatran is a direct thrombin inhibitor. Its antidote is idarucizumab. The other DOACs listed inhibit factor Xa.

PSI Pharmacy Practice Test

PSI Pharmacy Practice Test

PSI Pharmacology & Therapeutics 4