SA Endocrinology 3 - Hyperadrenocorticism and Other Adrenal Tumours Flashcards
What is hyperadrenocortism also known as?
Cushing’s Syndrome
What is cortisol secretion regulated by?
The hypothalamic-pituitary-adrenal axis
Describe how pituitary dependant hyperadrenocorticism occurs
Autonoumously functioning pituitary tumour causes excessive ACTH secretion. There is also bilateral adrenocortical hypertrophy and excessive cortisol secretion.
Describe how adrenal dependant hyperadrenocorticism occurs
Adreno-cortical tumour, typically carcinoma, causes unregulated cortisol secretion, independant of ACTH
What value is commonly raised on a serum biochemistry of hyperadrenocorticism?
ALP
Which urine test will exclude hyperadrenocorticism?
A nromal urine cortisol:creatinine ratio
What does the ACTH stimulation test show?
Adrenal reserve
What can a low dose dexamethasone stimulation test show?
Differentiation between PDH and ADH
Which drug can you use to medically treat hyperadrenocorticism?
Trilostane
What does trilostane inhibit?
3B-hydroxysteroid dehydrogenase
What is the most common adverse event to the medical treatment of hyperadrenocorticism?
Excessive adrenocortical suppression - iatrogenic hyperadrenocorticism
What is the drug duration of action of trilostane?
8-10 hours
What is the prognosis for hyperadrenocorticism managed with trilostane for PDH and ADH?
PDH - 3 years
ADH - 1 year
What is feline hyperaldosteronism also known as?
Conn’s syndrome
What is the classical presentation of a cat with hyperaldosteronism?
Hypokalaemic myopathy
