GP - Chest Pain

Question 1

What are some contraindications to prescribing NSAIDs?

Answer 1

1. Active GI bleeding / active GI ulcer
2. A Hx of GI bleeding related to previous NSAID therapy / Hx of GI perforation related to previous NSAID therapy
3. A Hx of recurrent GI haemorrhage (two or more distinct episodes) / Hx of recurrent GI ulceration (two or more distinct episodes)
4. A Hx of hypersensitivity/severe allergic reaction to an NSAID (including aspirin) e.g. asthma, rhinitis, angioedema or urticaria
5. Severe heart failure
6. Severe hepatic impairment i.e. serum albumin < 25 g/l or Child-Pugh score of 10 or more
7. Severe renal impairment i.e. eGFR <30 mL/minute/1.73 m2

Question 2

There are 5 conditions in which you should not prescribe: high dose ibuprofen (i.e. > 2400mg daily), diclofenac, aceclofenac or selective COX-2 inhibitors (e.g. Celecoxib or rofecoxib) - what are they?

Answer 2

1. Ischaemic heart disease
2. Inflammatory bowel disease (can’t prescribe selective COX-2 inhibitor only)
3. Peripheral arterial disease
4. Cerebrovascular disease
5. CHF

Question 3

What are the possible side-effects / risks of NSAIDs?

Answer 3

Side-effects of NSAIDs:

• Dyspepsia
• Upper GI complications:
  
  • Peptic ulcer
  • Perforation
  • Bleeding
• Increased risk of thrombotic events (worse with high-dose long term)
• Prolonged bleeding post surgery (due to inhibition of platelet aggregation)

Less Common:

• Cardiovascular & Renal complications:
  
  • MI, stroke, HF, HTN and renal failure
• Bronchospasm - exacerbate asthma
• Angioedema
• Skin reactions e.g. dermatitis, Stevens-Johnson syndrome & toxic epidermal necrolysis

Question 4

What are the mechanisms which underpin the cardiovascular and renal complications of NSAIDs?

Answer 4

Mechanism of Cardiovascular complications:

• Inhibition of COX-2 –> leads to suppression of prostacyclin –> vassocontriction + platelet aggregation (clotting)
  
  • Prostacyclin normally protects endothelial cells, produces vasodilation and interacts with platelets to antagonize aggregation
• Inhibition of COX-1 –> inhibits conversion of arachidonic acid to thromboxane A2 –> less thromboxane A2 –> thus reducing platelet aggregation + results in vasodilation
  
  • ​Thromboxane A2 is a potent platelet aggregator and vasoconstrictor
• Selective COX-2 inhibition = CV risk –> as it shifts balance, increasing thrombosis

Mechanism of Renal complications:

• NSAIDs inhibit synthesis of prostaglandins PGE2 & PGI2 which may result in:
  
  1. sodium (Na⁺) retention
  2. reduced renal blood flow
  3. renal failure

Question 5

What is the mechanism underpinning the GI complications associated with NSAIDs?

Answer 5

NSAIDs inhibit COX-1 –> reducing prostagladin levels –> increases gastric acid secretion & reduced bicarbonate secretion

• Selective COX-2 inhibitor NSAIDs (e.g. etoricoxib & celecoxib) exhibit reduced GI toxicity
• NSAID GI complications:
  
  • Dyspepsia
  • Peptic ulcer
  • Bleeding

Question 6

What are some risk factors for NSAID-induced GI adverse effects?

Answer 6

• Age > 65-yrs
• High dose NSAID
• Hx of GI ulcer, bleeding or perforation
• Medications: anticoagulants, steroids, SSRIs
• Comorbidities: CVD, hepatic or renal impairment
• Heavy smoking
• Excessive alcohol
• Hx of adverse reaction to NSAIDs

Question 7

Challenge:

Name as many differentials for chest pain as you can.

Answer 7

• Cardiac: MI, aortic stenosis, pericarditis, endocarditis
• GI: peptic ulcer, GI bleed, pancreatitis, GORD, cholangitis, cholecystitis
• Respiratory: pneumonia, pleurisy, PE, lung cancer
• MSK: muscular, costochondritis, shingles, pain secondary to statins
• Vascular: aortic dissection, aortic aneurysm

Question 8

What medications can increase the risk of GI complications when taken alongside NSAIDs?

Answer 8

1. Anticoagulants
2. Steroids
3. SSRIs

Question 9

What is Anchoring Bias?

Answer 9

A type of cognitive bias in which an individual depends too heavily on an initial piece of information

E.g. assuming a patient’s inital diagnosis in hospital is the correct diagnosis & behaving as such

Question 10

What is Availability Bias?

Answer 10

Availability Bias:

The tendency to let an example that comes to mind easily (because you have recently seen or been taught about it, or you had a particularly vivid experience of the case) affect your decision making or reasoning

E.g. reading about peptic ulcers and thinking the next abdo pain presentation is due to this

Question 11

What are the possible side-effects of iron supplementation i.e. Ferrous Sulphate?

Answer 11

• Abdo pain (over stomach) - cramp like
• Dark‘gritty’ stools
• Change in bowel habit - can be diarrhoea or constipation