adrenal disorders

Question 1

addison’s disease what it is and most common cause

Answer 1

primary adrenal failure

TB= commonest worldwide
autoimmune =commonest UK
destroy adrenal cortex

Question 2

symptoms addison’s

Answer 2

pigmentation
autoimmune vitiligo (patches of skin that lost colour)
no cortisol or aldosterone= low BP

Question 3

what is POMC

Answer 3

Pro-opio-melanocortin

cleaved to become ACTH/aMSH(a-melanocyte stimulating hormone)

Question 4

consequence of adrenocortical failure

Answer 4

low BP (postural hypotension)

hyponatraemia
hyperkalaemia

Low glucose due to glucocorticoid deficiency

High ACTH causing increased pigmentation

Eventual death due to severe hypotension

Question 5

Tests for addison’s

Answer 5

biochemistry: low Na/high K

9am cortisol=low (ACTH=high)

short synACTHen test
give 250ug synacthen IM
measure cortisol response (no response=addisons)

Question 6

treatment for primary adrenocortical failure - what needs replacing

Answer 6

-replace cortisol-
with hydrocortisone three times daily (10 + 5 + 2.5)
or
Prednisolone 3mg daily

-replace aldosterone
Fludrocortisone 50 to 100 mcg daily

-no need to replace adrenal sex steroid

Question 7

what to replace aldosterone

Answer 7

fludrocortisone 50-100mcg daily

not aldosterone as half life too short for safe once daily administration

Question 8

what does 11bHSD do and what does it stand for

Answer 8

11b-hydroxysteroid dehydrogenase

converts cortisol into cortisone(inactive) to protect aldosterone receptors (MR)

Question 9

cause of cushing’s

Answer 9

taking too many steroids(glucocorticoids)

pituitary dependent cushing’s disease

ectopic ACTH from lung cancer

adrenal adenoma secreting cortisol

Question 10

investigations for cushing’s

Answer 10

24hr urine collection for urinary free cortisol

blood diurnal cortisol level

low dose dexamethasone suppression test

Question 11

how to do dexamethasone suppression test to test for cushing’s

Answer 11

dexamethasone=artificial glucocorticoid.

healthy- cortisol suppressed to zero.

cushing’s- failure to suppress cortisol

Question 12

treatment for cushing’s drug list

Answer 12

metyrapone
ketoconazole
osilidrostat

Question 13

metyrapone MOA, use , SE

Answer 13

MOA: inhibit 11b-hydroxylase

use: control symptoms prior to surgery + better post-op recover.
Control symptoms after radiotherapy.

SE: hypertension on LT use
hirsutism

Question 14

ketoconazole MOA, use , SE

Answer 14

MOA: block 17a-hydroxylase- inhibit cortisol production

use: similar to metyrapone
control symptoms prior to surgery

SE: live damage- monitor liver function weekly, clinically and biochemically

Question 15

osilidrostat MOA

Answer 15

MOA- block 11b + 17a hydroxylase- inhibit cortisol production

Question 16

additional (more surgical treatment for cushing’s

Answer 16

Depends on cause
Pituitary surgery (trans-sphenoidal hypophysectomy)
Bilateral adrenalectomy
Unilateral adrenalectomy for adrenal mass

Question 17

what is conn’s syndrome

Answer 17

Benign adrenal cortical tumour (zona glomerulosa)
Aldosterone in excess

Question 18

effects of conn’s syndrome

Answer 18

Increases:
renal sodium reabsorption
renal potassium excretion
blood pressure

Question 19

conn’s syndrome diagnosis

Answer 19

primary hyperaldosteronism
renin-angiotensin system should be suppressed

Question 20

conn’s syndrome treatment

Answer 20

MR antagonist ie
spironolactone
epleronone

Question 21

what spironolactone do: MOA and SE

Answer 21

MR antagonist
blocks sodium resorption+ potassium excretion in kidney tubules (potassium sparing diuretic)

SE:
gynaecomastia

Question 22

epleronone- what is it

Answer 22

MR antagonist
similar affinity to spironolactone
less binding to androgen- better tolerated (less gynaecomastia)

Question 23

phaeochromocytomas what is it

Answer 23

adrenal MEDULLA tumour

secrete catecholamines
(adrenaline and nor-adrenaline)

Question 24

clinical features of phaeochromocytomas

Answer 24

(episodic/severe) Hypertension in young people (after abdominal palpation)

Severe hypertension can cause MI/stroke

High adrenaline can cause ventricular fibrillation + death

medical emergency

Question 25

management of phaeochromocytomas

Answer 25

surgery-
careful with prep as anaesthetic can cause hypertensive crisis

1) Alpha blockade(alpha receptors on arteries cause vasoconstriction)
—plus IV fluid if needed

2) Beta blockade prevent tachycardia