Antidiuretic Hormone Disorders Flashcards
What is meant by diabetes insipidus
Excess dilute urine
What are the restores of diabtes insipidus
Reduced production of ADH (vasopressin)
Kidneys do not retain as much water
Too much water passes from the body
Causing extreme thirst/polyuria
More dilute urine is produced
What are the features of a normal person
Hypothalamus produces vasopressin (ADH) which is stored in the pituitary gland
ADH released when water in the body becomes too Low
ADH retains water in the body by reducing the amount of eater lost through the kidneys
More concentrated urine as a result
What are the two types of diabetes insipidus
Pituitary (cranial)- the main type of
Lack of vasopressin (ADH) production (most common type)
Treatment is vasopressin or desmopressin
Nephrogenic (partial)
Kidneys doesn’t respond to ADH
Treatment: thiazide diuretics (paradoxical effect- does the opposite of what you expect it to do)
What is desmopressin
More potent and longer duration of action than vasopressin
No vasoconstrictor effect
Side effects:
Hyponatraemia
Nausea
What happens when you have too much ADH and how do you treat it
Increased ADH = body stores too much water = dilutes the salt concentration in the blood = hyponatraemia
Treatment:
Fluid restriction
Demeclocycline ( block the Renal tubular effect of ADH)
Tolvaptan (vasopressin antagonist)
AVOID rapid correction of hyponatraemia with tolvaptan
Causes osmotic demyelination = serious neurological events
