E23.2/N25.1
DESCRIPTION
Suspect diabetes insipidus in any child with polydipsia and polyuria. Infants may present with failure to thrive.
Central diabetes insipidus is due to deficiency of antidiuretic hormone.
Nephrogenic diabetes insipidus occurs if the kidney is unable to respond to antidiuretic hormone.
DIAGNOSTIC CRITERIA
- Pathological polyuria defined as excretion of >1.5 L/m² of urine. In infants, the corresponding value is >2.5 L/m² .
- Serum osmolality >300 mOsm/kg, with urine osmolality <300 mOsm/kg is suggestive of diabetes insipidus.
- A positive water deprivation test. (Only conduct under specialist supervision).
MEDICINE TREATMENT
Central diabetes insipidus (Specialist initiated)
Older children:
- Desmopressin, oral, 50–300 mcg/day 8 hourly.
- Titrate according to response. Use the lowest dose at which an antidiuretic effect is obtained.
- Maximum dose: 1200 mcg daily.
Infants or where oral administration is not feasible:
- Desmopressin, nasal spray, 10 mcg/day (0.1 mL), starting dose.
- Titrate according to response. Use the lowest dose at which an antidiuretic effect is obtained.
- Maximum daily dose: 30 mcg/day once or twice daily.
Note: Dosing of oral and nasal formulations is different owing to the difference in absorption rates.
The patient must have a phase of urinary dilution or breakthrough urination before the next dose to ensure that water intoxication does not result.
Nephrogenic diabetes insipidus
If no response to desmopressin.
Treat the underlying cause.
- Hydrochlorothiazide, oral, 0.5–1mg/kg/dose 12 hourly.
- Ibuprofen, oral, 5 mg/kg/dose 12 hourly.
REFERRAL
- All cases for evaluation.