Endocrinology Flashcards
Which drug should be given for mineralocorticoid deficiency?
Fludrocortisone
Which drug should be given for aldosterone deficiency?
Fludrocortisone
Which 3 drugs can be given for glucocorticoid deficiency?
(PhD) Prednisolone, hydrocortisone, dexamethasone
When are cortisol levels at their highest?
8-9am
When are cortisol levels at their lowest?
Midnight
2 ways in which aldosterone increases water resporption?
- Increase Na/K ATPase in DCT and collecting ducts
2. Insert Na channels in luminal aspect of collecting ducts
Which 3 anti-hypertensives will not interfere with aldosterone:renin ratio?
Verapamil, hydralazine, prazosin
What are the three screening tests for Cushing’s syndrome?
24-hour urine cortisol. Midnight salivary cortisol. Low dose (1mg) dexamethasone suppression test
If Cushing’s is suspected and screening tests are positive, what is the next test and what result would you see in Cushing’s disease?
ACTH will be elevated in Cushing’s disease or an ectopic tumour
If a patient has ACTH-dependent Cushing’s disease, what is the best next test that will differentiate a pituitary tumour from an ectopic tumour?
High dose (8 mg) dexamethasone suppression test will suppress ACTH and cortisol with a pituitary, but NOT with an ectopic tumour
Addison’s disease is due to a deficiency in which enzyme?
21-hydroxylase
If a patient has low early morning cortisol, which test should be next? What result would a normal person get?
Short synacthen test (ACTH stimulation). Normal is cortisol rise >500
In adrenal insufficiency, what prophylaxis should be done during times of stress? What if they are not tolerating PO intake?
Double dose of glucocorticoid (or hydrocortisone IV 25mg TDS if not tolerating PO)
Management of adrenal crisis?
Hydrocortisone 50mg IV TDS or q6h
Screening test for primary aldosteronism?
Aldosterone: renin ratio (elevated in PA)
