Therapeutic use of adrenal steroids

Question 1

Recall 4 examples of exogenous corticosteroids

Answer 1

1. Hydrocortisone
2. Dexamethosone
3. Prednisolone
4. Fludrocortisone

Question 2

Describe the protein-binding of hydrocortisone

Answer 2

It binds to CBG, like cortisol

Question 3

Compare the duration of action of 3 examples of corticosteroid

Answer 3

Dexamethosone>prednisolone>hydrocortisone

Question 4

Recall the main treatment pathway for primary adrenocortical failure

Answer 4

Treat lack of cortisol with dexamethosone/ prednisolone/ hydrocortisone
Treat lack of aldosterone with fludrocortisone

Question 5

Recall the main treatment pathway for secondary adrenocortical failure

Answer 5

ACTH deficiency so do not lack aldosterone - therefore only replace cortisol (dexamethosone/ prednisolone/ hydrocortisone)

Question 6

Recall the treatment of an acute addisonian crisis

Answer 6

1. IV 0.9% CaCl to rehydrate
2. High dose of IV hydrocortisone (will replace both aldosterone and cortisone as dose overwhelms 17BHSD to bind to GR and MR)
3. 5% dextrose if hypoglycaemic

Question 7

Compare the distribution of GRs and MRs

Answer 7

GRs = widely distributes, MRs = kidney

Question 8

Compare the selectivity of GRs and MRs

Answer 8

GR = selective for glucocorticoids
MR = do not distinguish between aldosterone and cortisol

Question 9

Recall the receptor sensitivity of hydrocortisone

Answer 9

GR with MR at high doses

Question 10

Recall the receptor sensitivity of prednisolone

Answer 10

GR with weak MR

Question 11

Recall the receptor sensitivity of hydrocortisone

Answer 11

Purely GR

Question 12

Recall the receptor sensitivity of fludrocortisone

Answer 12

MR