Posterior pituitary hormones Flashcards
What is vasopressin?
ADH, antidiuretic hormone.
What is vasopressin used to treat?
Diabetes insipidus as is its analogue desmopressin.
Dosage is tailored to produce a slight diuresis every 24 hours to avoid water intoxication. Treatment may be required for a limited period only in diabetes insipidus following trauma or pituitary surgery.
How does desmopressin differ from vasopressin? [3]
Desmopressin is more potent, has a longer duration of action and has no vasoconstrictor effect.
How and when is desmopressin given?
Desmopressin is given by mouth or intranassally for maintenance therapy, and by injection in the postoperative period or in unconscious patients.
How can desmopressin be used in the differential diagnosis of diabetes insipidus?
A dose of desmopressin is given intramuscularly or intranasally, restoration of the ability to concentrate urine after water deprivation confirms a diagnosis of cranial diabetes insipidus. Failure to respond occurs in nephrogenic diabetes insipidus.
In nephrogenic and partial pituitary diabetes insipidus benefit may be gained from the paradoxical antidiuretic effect of what?
Thiazides.
The unlicensed use of carbamazepine is sometimes useful in partial pituitary diabetes insipidus, how may it act?
By sensitising the renal tubules to the action of remaining endogenous vasopressin.
Desmopressin can be used to boost factor VIII concentration in mild to moderate haemophillia and in what other disease?
von Willebrand’s disease.
Vasopressin infusion is used to control what complication of portal hypertension, prior to more definitive treatment?
Variceal bleeding.
What is demeclocycline hydrochloride used in the treatment of?
Hyponatraemia resulting from inappropriate secretion of antidiuretic hormone, if fluid restriction alone does not restore sodium concentration or is not tolerable.
What is tolvaptan?
A vasopressin V2-receptor antagonist licensed for the treatment of hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone secretion; treatment duration with tolvapatan is determined by the underlying disease and its treatment.
