hyperadrenals

Question 1

features of cushings

Answer 1

excess cortisol centripetal obesity, proximal (trunk) myopathy, moon face and buffalo hump, hypertension and hypokalaemia, striae, thin skin= bruising (immunosupression), and osteoporosis and diabetes

Question 2

causes of cushings syndrome (from any cause)

Answer 2

most common taking too many steroids (mainly corticosteroids) endogenous causes are mainly pituitary dependent cushings disease (disease caused by pituitary fault), but also ectopic ACTH from lung cancer, and adrenal adenoma= excess cortisol

Question 3

investigating cushings syndrome with dose and why DIAGRAM

Answer 3

24hr urine collection for cortisol OR blood diurnal (different times of day) cortisol levels as cortisol highest in morning, and lowest during midnight (as asleep) also low dose (0.5mg every 6 hrs for 48 hrs) dexamethasone supression test (artifical steroid that stops cortisol production to 0 if normal- )

Question 4

problem with dexamethasone

Answer 4

doesn’t tell you cause of cushings, as any cause will fail to surpress cortisol

Question 5

example of diagnosis using dexamethsone test

Answer 5

basal cortisol (9am) 800nM, cortisol after test 680

Question 6

main treatment of cushings syndrome, and problem with solution

Answer 6

main treatment is surgery, but patients are immunosurpressed (risk of infection during surgery), so must ensure they recover well after surgery- thus drugs are used to reduce cortisol

Question 7

adrenal cortex+ synthesis of cortisol

Answer 7

derived from cholesterol glomerulosa= aldosterone, fasciculata= cortisol, reticularis= SOME sex steroids

Question 8

metyrapone mechanism

Answer 8

inhibits 11beta-hydroxylase, which converts 11-deoxycortisol to cortisol (ie deoxycortisol rises- has no negative feedback) enzyme also converts 11-deoxycorticosterone to corticosterone, so this is also inhibited

Question 9

uses of metyrapone

Answer 9

controls cushings before surgery, adjusting dose according to cortisol controlling cushing after radiotherapy (slow to take effect- used for pituitary tumour)

Question 10

problem with metyrapone

Answer 10

deoxycorticosterone accumulates, and it has aldosterone-like properties= salt retention+ hypertension many of precursors accumulate, which are also used to produce sex hormones, thus more androgen production in women= HIRSUTISM

Question 11

ketoconazole- uses- who used for and mechanism

Answer 11

also reduces cortisol production in cushings prior to surgery- is antifungal agent as a tablet that is not usually used as potential toxic to liver, but used for a select group of patients inhibits 17alpha hydroxylase

Question 12

treating cushings after drugs

Answer 12

depending on cause, pituitary surgery can be used (transphenoidal surgery- removing tumour through nasal cavity) bilateral/unilateral adrenalectomy (no ACTH production)

Question 13

what is conns syndrome+ main effects

Answer 13

benign adrenal cortical tumour of zona glomerulosa= excess aldosterone= hypertension+ hypokalemia (retain sodium and lose potassium)

Question 14

diagnosis of conns (primary hyperaldosteronism)

Answer 14

measure aldosterone- should be high measure renin- should be low ie primary hyperaldosteronism, not secondary

Question 15

overview of treatment of conns

Answer 15

rather than blocking production of hormone, the receptor is blocked

Question 16

spironolactone mechanism+ pharmacokinetics

Answer 16

converted to canrenone, a competitive antagonist of mineralocorticoid receptor (MR), blocking Na+ in and K+ out ie potassium sparing tablet+ metabolised in liver

Question 17

problem with spironolactone

Answer 17

not very specific to MR receptor- binds to progesterone receptor (menstrual problems) and inhibits androgen receptor (gynaecomastia)

Question 18

epleronone advantage

Answer 18

also MR antagonist with similar affinity, but less binding to other receptors= less side effects

Question 19

what are phaeochromocytomas

Answer 19

tumour of adrenal medulla= XS adrenaline+ NA

Question 20

clinical features of phaeo

Answer 20

INTERMITTENT severe episodes of hypertension- often in young pp= MI/stroke: can also cause ventricular fibrillation and death sweating sick/headache/dizziness anxiety more common in certain inherited conditions

Question 21

treatment of phaeo

Answer 21

surgery, although patient needs careful preparation of anesthetic, as it can cause a hypertensive attack alpha blockade is needed (possibly IV fluid before to prevent large decrease in BP), and THEN beta blockade to prevent tachycardia- once this is done, surgery can occur

Question 22

facts about phaeochromocytone

Answer 22

10% extra-adrenal (not from adrenal gland), 10% malignant, 10% bilateral extremely rare