Mineralocorticoids

Question 1

Mineralocorticoid activity

Answer 1

Increased Na reabsorption = water retention (maintains blood volume and pressure)
Potassium excretion = prevents hyperkalaemia

Overall, regulates water balance and is used if water retention is beneficial i.e. there is low BP

Question 2

Fludrocortisone

Answer 2

• Most potent
• Used in neuropathic postural hypotension (diabetes) or adrenal insufficiency due to septic shock
• Anti-inflammatory effect of no clinical relevance

Question 3

Hydrocortisone

Answer 3

• Significant activity
• Should not be used for long-term disease suppression due to fluid retention.
• Useful for short-term basis via IV for emergency (life-threatening asthma or thyrotoxicosis)

Question 4

Side effects

Answer 4

Na+ and water retention = hypertension
K+ and Ca2+ loss

Question 5

Side effects - frequency

Answer 5

Most marked with fludrocortisone
Significant with:
- hydrocortisone
- corticotrophin
- tetracosactide
Neglible with:
- betamethasone
- dexamethasone