What is the treatment for Diabetes Insipidus (DI)?

Treatment for Diabetes Insipidus

The treatment for diabetes insipidus depends on the type, with central diabetes insipidus requiring desmopressin replacement therapy and nephrogenic diabetes insipidus requiring thiazide diuretics combined with prostaglandin synthesis inhibitors and dietary modifications. 1, 2

Diagnosis and Classification

• Suspect diabetes insipidus in patients with polyuria, polydipsia, and inappropriately dilute urine (urine osmolality <200 mOsm/kg H₂O) with high-normal or elevated serum sodium 1
• Measure serum sodium, serum osmolality, and urine osmolality as initial biochemical work-up 1
• Plasma copeptin levels >21.4 pmol/l suggest nephrogenic diabetes insipidus, while levels <21.4 pmol/l indicate central diabetes insipidus 1, 2
• Early genetic testing is recommended for suspected nephrogenic diabetes insipidus 1

Treatment for Central Diabetes Insipidus

• First-line treatment: Desmopressin (DDAVP) 3
  • Available forms: intranasal spray, oral tablets, sublingual lyophilisate, injectable 3, 4
  • Dosage: Individualized based on response
    • Intranasal: Adults 0.1-0.4 mL daily (10-40 μg), divided into 2-3 doses 3
    • Intranasal: Children 0.05-0.3 mL daily (5-30 μg), divided into 1-2 doses 3
  • Monitor for water intoxication and hyponatremia 5
• Free access to fluids to prevent dehydration 1
• Regular monitoring of serum electrolytes, urine volume, osmolality, and body weight 1, 6

Treatment for Nephrogenic Diabetes Insipidus

• Free access to fluid is essential to prevent dehydration, hypernatremia, growth failure, and constipation 1, 2
• Dietary modifications:
  • Low salt diet (≤6 g/day) 1, 2
  • Low protein diet (<1 g/kg/day) 1
  • Normal-for-age milk intake for infants (instead of water) to ensure adequate caloric intake 7, 1
• Pharmacological treatment:
  • Thiazide diuretics (can reduce urine output by up to 50% when combined with low-salt diet) 7, 1
  • Add amiloride if hypokalemia develops 7
  • Prostaglandin synthesis inhibitors (COX inhibitors) 7, 1
  • Close monitoring of fluid balance, weight, and biochemistry when starting treatment 7
• Consider tube feeding in infants with repeated vomiting, dehydration, or growth failure 7, 1

Monitoring and Follow-up

• Regular assessment of height and weight, especially in children 1
• Monitor basic plasma biochemistry (Na, K, Cl, HCO₃, creatinine, osmolality) 1
• Kidney ultrasound every 2 years to check for urinary tract dilatation 1, 2
• Evaluate treatment efficacy via urine osmolality, urine output, weight gain, and growth 1

Emergency Management

• Each patient should have an emergency plan with a letter explaining their diagnosis 1, 2
• For fasting >4 hours: intravenous 5% dextrose in water at maintenance rate 1
• Intravenous rehydration with 5% dextrose solution for dehydration 1, 2
• Close observation of clinical status, fluid balance, body weight, and serum electrolytes 1

Important Considerations

• Risk of hyponatremia with desmopressin therapy requires careful dose titration and monitoring 5
• Drug treatment for nephrogenic diabetes insipidus may be discontinued with increasing age 7
• Patients capable of self-regulating should determine their fluid intake based on thirst sensation 7, 1
• Dietitian support is recommended for patients with nephrogenic diabetes insipidus 7