Drug of Choice Cheatsheet — Respiratory MRCP

TL;DR

This drug of choice cheatsheet — respiratory focus (MRCP Part 1) is your fast-track summary of key pharmacological choices in common respiratory conditions. It covers emergency, maintenance, and infection-specific drugs tested frequently in MRCP Part 1, complete with mini-cases, pitfalls, and evidence-based study tips. Perfect for last-minute recall.

Why this matters

The MRCP Part 1 exam doesn’t just test your theoretical grasp of respiratory medicine — it measures clinical reasoning under pressure. Many candidates lose marks by mixing emergency management with long-term therapy or by missing contraindications (like β-blockers in asthma).

This guide brings together the most examinable “drug of choice” facts, drawn from authoritative sources such as the British National Formulary (BNF), NICE Clinical Knowledge Summaries, and the British Thoracic Society (BTS) Guidelines.

For structured revision, review the MRCP Part 1 overview and test your recall in Free MRCP MCQs.

High-Yield Drug of Choice Table (Respiratory)

Condition	Drug of Choice	Key Exam Tip
Acute severe asthma	Salbutamol (nebulised β₂-agonist)	First-line in all ages; combine with ipratropium if partial response.
COPD exacerbation	Nebulised salbutamol + controlled O₂	Keep O₂ saturation 88–92%; add oral prednisolone ± antibiotics.
Community-acquired pneumonia (CAP)	Amoxicillin	Add macrolide if atypical suspicion; doxycycline if penicillin-allergic.
Atypical pneumonia	Macrolide (Clarithromycin/Azithromycin)	Think Mycoplasma, Chlamydophila, Legionella.
Hospital-acquired pneumonia	Co-amoxiclav or Piperacillin-Tazobactam	Cover Gram-negatives and Staphylococcus aureus.
Active pulmonary tuberculosis	Rifampicin, Isoniazid, Pyrazinamide, Ethambutol (RIPE)	2-month intensive + 4-month continuation phase.
Pneumocystis jirovecii pneumonia (PCP)	Co-trimoxazole (TMP-SMX)	Add prednisolone if PaO₂ < 9.3 kPa or A-a gradient > 35 mm Hg.
Cystic fibrosis with Pseudomonas infection	Inhaled Tobramycin / Colistin	Chronic suppression reduces exacerbations; monitor renal function.
Sarcoidosis (symptomatic)	Oral Prednisolone	Don’t treat asymptomatic Stage I disease.
Pulmonary embolism (acute)	LMWH (e.g., Enoxaparin)	Bridge to DOAC or warfarin once stable.
Allergic bronchopulmonary aspergillosis	Prednisolone + Itraconazole	Seen in asthma/CF with eosinophilia; taper steroids slowly.

Top 5 Most Tested Subtopics

1. Asthma step-wise management: SABA → ICS → LABA → Oral steroid; know BTS/SIGN chart.

2. Antitubercular drugs: Mechanisms, side effects, and monitoring.

3. Pneumonia regimens: CAP vs. HAP, especially in penicillin allergy.

4. VTE management: LMWH initiation, DOAC maintenance, and contraindications.

5. CF chronic therapy: Antibiotic rotations and mucolytic combinations.

   
   

Quick Practical Examples / Mini-Cases

Case 1: Acute Asthma A 26-year-old presents with wheeze, SpO₂ = 88%. Nebulised salbutamol offers partial relief. Next step: Add nebulised ipratropium bromide and give IV hydrocortisone.💡 Avoid sedatives and β-blockers even if hypertensive.

Case 2: Tuberculosis Adverse EffectA patient on RIPE therapy reports blurred vision. Likely drug: Ethambutol → optic neuritis. Stop and replace; check visual acuity regularly.

Case 3: COPD Oxygen Trap A COPD patient on uncontrolled 100% O₂ becomes drowsy. Reason: CO₂ retention due to loss of hypoxic drive. Fix: Use Venturi mask 24–28%, target SpO₂ = 88–92%.

Evidence-Based Study Checklist

1. ✅ Cluster learning: Revise one disease pair daily (Asthma + COPD, TB + Pneumonia).

2. ✅ Use spaced repetition: Flashcards with Condition → DOC → Adverse effect.

3. ✅ Simulate exam pressure: Attempt mixed topics via Free MRCP MCQs.

4. ✅ Cross-reference with guidelines: BNF + BTS for current protocols.

5. ✅ Take timed mocks: Practise decision-making speed in mock tests.

6. ✅ Keep updates handy: NICE antibiotic guidance is frequently updated.

7. ✅ Visualise pathways: Draw your own asthma step ladder and PE treatment flowchart.

   
   

Common Pitfalls (and Fixes)

• ❌ Mixing acute and chronic management → Fix: Memorise “emergency → maintenance → preventive” order.

• ❌ Neglecting contraindications → Fix: Beta-blockers worsen asthma; note exceptions (cardio-selective in HF).

• ❌ Over-oxygenation in COPD → Fix: Controlled O₂, 88–92%.

• ❌ Ignoring toxicity signs → Fix: Ethambutol → optic neuritis; Isoniazid → peripheral neuropathy (add pyridoxine).

• ❌ Using wrong empiric antibiotic → Fix: Always confirm CAP vs. HAP origin and allergy status.

  
  

FAQs

1. How many respiratory pharmacology questions appear in MRCP Part 1?Typically 8–12 questions per paper, spanning asthma, TB, pneumonia, and anticoagulation.

2. Are NICE or BTS guidelines directly tested?

Not word-for-word, but exam answers usually align with them — revise their principles.

3. How can I memorise drug of choice lists efficiently?

Use digital flashcards or mnemonic columns. Focus on differentiating similar drugs (e.g., LABA vs. SABA).

4. Are dosages required for MRCP Part 1?

No. The exam tests drug identification, not exact doses.

5. What’s the best resource to practise MRCP pharmacology?

Combine Crack Medicine’s mock tests with the BNF for real-world clinical logic.

Ready to start?

Respiratory pharmacology demands precision under pressure. Strengthen your recall with interactive learning — start from the MRCP Part 1 overview, reinforce through Free MRCP MCQs, and challenge yourself with a full mock test. Crack Medicine’s platform brings current guidelines, explanations, and analytics together for focused progress.

Sources

1. MRCP(UK) Part 1 Examination Syllabus – Official Website

2. British National Formulary (BNF)

3. NICE Clinical Knowledge Summaries – Respiratory Topics

4. British Thoracic Society Guidelines – Asthma, COPD, Pneumonia

5. World Health Organization – Tuberculosis Treatment Guidelines