GPhC Clinical Therapeutics 2 — Questions and Answers
Question 1: A patient with chronic heart failure is being managed with ramipril and bisoprolol. Despite optimal doses, they remain symptomatic (NYHA class III). According to NICE, which additional medication should be considered?
- Amlodipine
- Spironolactone (or eplerenone) (Correct answer)
- Digoxin as first add-on
- Furosemide dose increase only
Correct answer: Spironolactone (or eplerenone)
NICE recommends adding a mineralocorticoid receptor antagonist (MRA) such as spironolactone or eplerenone for patients with heart failure with reduced ejection fraction who remain symptomatic despite optimal ACE inhibitor and beta-blocker therapy. This is established step 3 in the heart failure treatment pathway.
Question 2: Which of the following medicines requires therapeutic drug monitoring (TDM) due to its narrow therapeutic index?
- Amoxicillin
- Lithium (Correct answer)
- Omeprazole
- Metformin
Correct answer: Lithium
Lithium has a very narrow therapeutic index — the difference between a therapeutic dose and a toxic dose is small. Regular serum lithium monitoring is essential (target range 0.4-1.0 mmol/L for maintenance). Toxicity can cause renal failure, seizures, and cardiac arrhythmias.
Question 3: A patient with COPD is prescribed a LAMA/LABA combination inhaler. They continue to have frequent exacerbations. According to NICE, what should be considered next if the patient has features suggesting asthmatic/eosinophilic disease?
- Add oral theophylline
- Escalate to triple therapy by adding an inhaled corticosteroid (ICS) (Correct answer)
- Switch to a short-acting bronchodilator only
- Start prophylactic antibiotics
Correct answer: Escalate to triple therapy by adding an inhaled corticosteroid (ICS)
NICE recommends escalating to triple therapy (LAMA + LABA + ICS) for COPD patients with asthmatic features or raised eosinophils who continue to exacerbate despite dual bronchodilator therapy. The ICS component addresses the eosinophilic inflammation driving the exacerbations.
Question 4: A patient on warfarin presents with an INR of 8.5 with no active bleeding. According to NICE/BNF guidance, what is the most appropriate management?
- Administer vitamin K 5mg intravenously immediately
- Withhold warfarin and give oral vitamin K 1-5mg; recheck INR in 24 hours (Correct answer)
- Continue warfarin at a reduced dose
- Administer fresh frozen plasma
Correct answer: Withhold warfarin and give oral vitamin K 1-5mg; recheck INR in 24 hours
For an INR above 8.0 with no bleeding, the BNF recommends stopping warfarin and giving oral phytomenadione (vitamin K) 1-5mg. The INR should be rechecked after 24 hours. IV vitamin K and fresh frozen plasma are reserved for cases with major bleeding.
Question 5: A newly diagnosed asthma patient is prescribed a salbutamol inhaler. They are using it four times per week. According to the BTS/SIGN stepwise approach, what should happen next?
- Continue with salbutamol alone as needed
- Add a regular low-dose inhaled corticosteroid (ICS) (Correct answer)
- Start a long-acting beta-agonist (LABA) without ICS
- Prescribe oral montelukast as monotherapy
Correct answer: Add a regular low-dose inhaled corticosteroid (ICS)
Using a reliever inhaler three or more times per week indicates uncontrolled asthma. BTS/SIGN guidelines recommend stepping up to a regular low-dose ICS (e.g., beclometasone 200-400 micrograms/day) at Step 2. A LABA should never be used without an ICS in asthma.
Question 6: Which of the following is a recognised serious interaction between clarithromycin and simvastatin?
- Reduced absorption of simvastatin
- Increased risk of rhabdomyolysis due to CYP3A4 inhibition (Correct answer)
- Decreased antibiotic efficacy
- Hepatoprotective synergy
Correct answer: Increased risk of rhabdomyolysis due to CYP3A4 inhibition
Clarithromycin is a potent CYP3A4 inhibitor. Simvastatin is extensively metabolised by CYP3A4. Co-administration significantly increases simvastatin plasma levels, greatly increasing the risk of myopathy and rhabdomyolysis. This combination should be avoided — simvastatin should be suspended during clarithromycin treatment.
GPhC Clinical Therapeutics 2
A patient with chronic heart failure is being managed with ramipril and bisoprolol.
Despite optimal doses, they remain symptomatic (NYHA class III).
According to NICE, which additional medication should be considered?