Pharmacology and Pharmacotherapy
Core concepts
Candidates must master receptor pharmacology (agonists, partial agonists, inverse agonists, antagonists, competitive vs non-competitive), dose–response relationships, therapeutic index, and the pharmacokinetic parameters: bioavailability, volume of distribution, clearance, half-life, and the meaning of zero- vs first-order kinetics. Know the major drug classes by mechanism and by first-line indication: antihypertensives (ACE inhibitors, ARBs, CCBs, diuretics), antidiabetics (metformin, sulfonylureas, insulins, SGLT2 inhibitors), antibiotics (β-lactams, macrolides, fluoroquinolones, aminoglycosides), anticoagulants (heparins, warfarin, DOACs), analgesics (NSAIDs, opioids, paracetamol), and drugs for asthma/COPD. Understand key adverse effects and contraindications - e.g. ACE-inhibitor cough and angioedema, aminoglycoside nephro/ototoxicity, NSAID gastric and renal risk, warfarin–drug/food interactions.
Traps
Questions test mechanism over brand names, and often present a patient scenario where the correct answer is 'stop the drug' rather than 'add another'. Watch for first-line vs add-on therapy confusion, and for contraindications hidden in the vignette (e.g. NSAIDs in renal impairment, β-blockers in asthma). Partial agonists (e.g. buprenorphine) are a frequent trap.
Rule of thumb
For any pharmacotherapy question, apply the sequence: identify the indication → confirm first-line agent → check contraindications and interactions in the patient described → consider monitoring. If the scenario describes an adverse effect, the answer is usually to withdraw the culprit, not to treat through it.
Worked example
A patient on an ACE inhibitor develops a persistent dry cough. The mechanism is bradykinin accumulation. The correct action is to switch to an ARB, which does not inhibit bradykinin breakdown, rather than adding an antitussive.