Management of chronic diabetes insipidus
Diabetes insipidus causing mild polyuria (up to 3 litres per day) can safely be left untreated, provided the patient has ready access to water.
Diabetes insipidus causing moderate to severe polyuria can cause hypernatraemia. Mild hypernatraemia can usually be managed with increased water intake (see here for more information about management of hypernatraemia if required).
For ongoing management of polyuria, desmopressin (a synthetic analogue of arginine vasopressin) may be required. To minimise the risk of hyponatraemia associated with desmopressin, use the minimum effective dose required to control polyuria. Advice from an endocrinologist may be necessary to guide management decisions.
In adults, oral desmopressin is preferred over intranasal desmopressin, as it is less likely to cause symptomatic hyponatraemia. For arginine vasopressin replacement in an adult, use:
1 desmopressin 100 micrograms orally, 2 to 3 times daily. Adjust the dose according to response (symptoms and electrolytes). Maintenance dose is usually between 100 and 200 micrograms orally, 2 to 3 times daily diabetes insipidus, chronic (adult) desmopressin
OR
2 desmopressin 5 to 10 micrograms intranasally, once or twice daily. Adjust the dose according to response (symptoms and electrolytes). Maintenance dose is usually between 10 and 20 micrograms, once or twice daily. desmopressin
During pregnancy, the desmopressin dose usually needs to be increased because the clearance of arginine vasopressin increases.
Treatment of central diabetes insipidus in neonates, infants and children is difficult, and desmopressin should only be started and adjusted by a specialist. For arginine vasopressin replacement in children, a reasonable regimen is:
1 desmopressin intranasally diabetes insipidus, chronic (child) desmopressin
child between 1 month and 2 years: 2.5 to 5 micrograms, once or twice daily, adjusted according to response (symptoms and electrolytes)
child older than 2 years: 5 to 20 micrograms, once or twice daily, adjusted according to response (symptoms and electrolytes)
OR
1 desmopressin orally desmopressin
child between 1 month and 2 years: 10 micrograms, 2 to 3 times daily, adjusted according to response (symptoms and electrolytes)
child older than 2 years: 50 to 100 micrograms, 2 to 3 times daily, adjusted according to response (symptoms and electrolytes).
Intranasal desmopressin solution can be given orally if small doses are needed for infants. Hydrochlorothiazide and infant formula with a low renal solute load can also be used in infants under specialist management.
The desmopressin intranasal solution is delivered by a tube (rhinyle) or spray. The tube delivers fractional doses from 5 micrograms upwards; the spray delivers a fixed 10 microgram dose. For doses below 5 micrograms, dilution by a paediatric pharmacist is required. The dose conversion between the nasal and oral formulations is not clear. One 10 microgram nasal spray may equate to 400 micrograms of the tablet formulation. The dose should be retitrated if switching between formulations.
Patients with adequate thirst perception should be instructed to drink to thirst. Patients without adequate thirst perception require a fluid intake plan, developed by an endocrinologist, with consideration of factors such as gender, body mass, and climate (eg temperature, humidity).