How is diabetes insipidus managed?

Management of Diabetes Insipidus

Desmopressin is the treatment of choice for central diabetes insipidus, while nephrogenic diabetes insipidus requires thiazide diuretics combined with NSAIDs plus dietary sodium restriction—but free access to fluids is absolutely essential for all patients regardless of type. 1, 2, 3

Initial Diagnostic Workup

Before initiating treatment, establish the type of diabetes insipidus through specific testing:

• Measure serum sodium, serum osmolality, and urine osmolality to confirm inappropriately dilute urine (typically <200 mOsm/kg H₂O) 1, 2
• Check plasma copeptin levels to distinguish between central and nephrogenic DI: levels <21.4 pmol/L indicate central DI, while levels >21.4 pmol/L suggest nephrogenic DI 1, 2
• Order genetic testing early in suspected nephrogenic DI cases, particularly in symptomatic females and male offspring of known carriers 1, 2

Management of Central Diabetes Insipidus

Desmopressin Therapy

Desmopressin (DDAVP) is the first-line agent and can be administered via multiple routes depending on clinical circumstances 1, 3, 4:

• Intranasal route is preferred for outpatient management when nasal passages are patent 3, 5
• Oral/sublingual lyophilisate provides better bioavailability than tablets and melts under the tongue 5
• Subcutaneous administration should be used for infants or patients with postoperative/posttraumatic brain injury requiring close monitoring 5
• Parenteral route is indicated when intranasal delivery is compromised by nasal congestion, blockage, discharge, atrophic rhinitis, nasal packing, impaired consciousness, or following transsphenoidal surgery 3

Dosing Strategy

• Patients should titrate to the minimal effective dose that prevents excessive polyuria, particularly at night, rather than following rigid prescriptions 5
• Patient education is critical to avoid water intoxication and hyponatremia, the major complication of desmopressin therapy 6, 5

Management of Nephrogenic Diabetes Insipidus

Pharmacological Treatment

Thiazide diuretics combined with prostaglandin synthesis inhibitors (NSAIDs) are recommended for symptomatic patients 1, 2:

• Thiazides with low-salt diet reduce diuresis by up to 50% through mild volume depletion and increased proximal sodium/water reabsorption 1, 2
• Add amiloride if hypokalemia develops from thiazide therapy 2
• NSAIDs enhance collecting duct water permeability and should be added to the regimen 1, 2
• Discontinue NSAIDs during pregnancy and consider stopping once patients reach adulthood or achieve complete continence 2

Dietary Modifications

Restrict dietary sodium to ≤6 g/day and protein to <1 g/kg/day with dietetic counseling to reduce renal osmotic load and minimize urine volume 2:

• Infants should receive normal-for-age milk intake instead of water to ensure adequate caloric intake 2
• Consider tube feeding (nasogastric or gastrostomy) for infants and children with repeated vomiting, dehydration episodes, or failure to thrive 1, 2

Universal Management Principles for All Types

Fluid Management

Free access to fluid is absolutely essential in all patients with DI to prevent dehydration, hypernatremia, growth failure, and constipation 1, 2:

• Patients capable of self-regulating should determine fluid intake based on thirst sensation rather than prescribed amounts 1, 2, 7
• Patients who cannot self-regulate should be offered water frequently with close monitoring 2
• When fasting is required (>4 hours), administer intravenous 5% dextrose in water at maintenance rate with close monitoring 2

Emergency Preparedness

Each patient should have an emergency plan including a letter explaining their diagnosis with specific advice regarding intravenous fluid management 2:

• Use intravenous rehydration with 5% dextrose for acute decompensation 2
• Monitor clinical status closely including neurological condition, fluid balance, body weight, and serum electrolytes 2

Monitoring and Follow-up

Regular Assessments

• Monitor height and weight regularly, especially in children 2
• Check basic plasma biochemistry (Na, K, Cl, HCO₃, creatinine, osmolality) and urine osmolality 2
• Perform kidney ultrasound at least every 2 years to monitor for urinary tract dilatation and bladder dysfunction caused by polyuria 2
• Evaluate treatment efficacy via urine osmolality, urine output, weight gain, and growth 2

Common Pitfalls to Avoid

Watch for decreased responsiveness or shortened duration of effect after 6 months of desmopressin therapy, which may be due to local peptide inactivation rather than antibody development 3:

• Close monitoring of serum osmolality is essential when desmopressin is used with other medications affecting water balance 6
• Careful dose titration when initiating therapy reduces the risk of hyponatremia 6