Antidiuretic hormone disorders

Question 1

Diabetes insipidus

Answer 1

is a rare condition where you produce a large amount of urine (polyuria) and often feel thirsty (polydipsia).

Question 2

Cranial diabetes insipidus.

Answer 2

• Vasopressin (antidiuretic hormone) + Desmopressin are used in the treatment of cranial diabetes insipidus.
• Dosage is tailored to produce a slight diuresis every 24 hours to avoid water intoxication.
- Desmopressin can also be used in the differential diagnosis of diabetes insipidus. After taking a dose… if the patient can concentrate their urine after losing water (desmopressin stimulates diuresis) this means they have cranial diabetes insipidus.

Question 3

Treatment of ADHD

Answer 3

Is desmopressin which is more potent and has a longer duration of action than Vasopressin. It is used in diabetes insipidus + nocturnal enuresis. Unlike vasopressin, it has no vasoconstrictor effect. It is given orally or intranasally for maintenance therapy + by injection in the post-operative period or in unconscious patients.

Question 4

Nephrogenic diabetes insipidus

Answer 4

. If the patient does not respond to desmopressin, they have nephrogenic diabetes insipidus… which is treated with thiazides.

Question 5

Desmopressin, Patient and carer advice

Answer 5

• Hyponatraemic convulsions: patients being treated for primary nocturnal enuresis (bedwetting) should be warned to avoid fluid overload (including during swimming) and to stop taking desmopressin during an episode of vomiting or diarrhoea (until fluid balance normal)