Diabetes Insipidus Flashcards
How is ADH secretion stimulated (3 steps)?
Volume contraction increases ECF osmolality
Stimulates osmoreceptors (hypothalamus)
Stimulates ADH secretion
What does ADH do?
Stimulates reabsorption of water in DCT and collecting ducts, decreasing ECF osmolality.
What is ADH (pitressin) used for?
Used to differentiate between central (signs go away) and nephrogenic (signs don’t go away) DI
How is ADH (pitressin) used?
IM or IV over 1 hour in LRS or 5% dextrose.
What is central DI?
ADH deficiency
What is nephrogenic DI?
Impaired response of kidneys to ADH
How do you treat central DI?
Desmopressin, synthetic ADH analog.
Why do we use desmopressin instead of natural ADH to treat central DI?
More potent, longer duration (10-27 hrs vs. 20 minutes).
How is desmopressin administered?
Parenterally or nasal drops into conjunctival sac.
What is the drug of choice for treating central DI in dogs and cats?
Desmopressin.
What is a useful restriction in cases of both central and nephrogenic DI?
Restricting sodium chloride intake.
What is the drug of choice to treat nephrogenic DI?
Thiazide diuretics
