What is the treatment for diabetes insipidus?

Treatment of Diabetes Insipidus

For central diabetes insipidus, desmopressin (DDAVP) is the first-line treatment, administered intranasally at 10-40 mcg or parenterally at 2-4 mcg IV/SC, with careful monitoring for hyponatremia. 1, 2

Initial Diagnostic Workup

Before initiating treatment, confirm the type of diabetes insipidus:

• Measure serum sodium, serum osmolality, urine volume, and urine osmolality as baseline biochemical assessment 3, 1
• Obtain plasma copeptin levels: values <21.4 pmol/l suggest central DI (AVP deficiency), while levels >21.4 pmol/l indicate nephrogenic DI 3, 4
• Perform MRI of the sella with and without IV contrast using high-resolution pituitary protocols to identify hypothalamic-neurohypophyseal axis abnormalities, mass lesions (craniopharyngioma, germinoma, Langerhans cell histiocytosis, metastases), inflammatory processes (sarcoidosis, lymphocytic hypophysitis), or traumatic etiologies 3
• Verify response to desmopressin administration: response confirms central DI, while lack of response indicates nephrogenic DI 3

Treatment by Type

Central Diabetes Insipidus

Desmopressin (DDAVP) is the drug of choice due to its selective antidiuretic activity without adverse vasopressor effects 2, 5:

• Intranasal dosing: 10-40 mcg daily, divided into 1-2 doses 1, 2
• Parenteral dosing: 2-4 mcg IV or subcutaneously 1, 2
• Oral formulation: Available but requires higher doses due to lower bioavailability 1

Fluid management: Allow ad libitum access to fluids, with patients relying on their thirst sensation rather than prescribed amounts when capable of self-regulation 3, 4

Nephrogenic Diabetes Insipidus

Desmopressin is ineffective and not indicated for nephrogenic DI 1. Treatment focuses on:

• Thiazide diuretics combined with prostaglandin synthesis inhibitors (NSAIDs) as first-line therapy, which can reduce urine output by up to 50% initially 3
• Low-salt diet to reduce renal osmotic load 3
• Amiloride addition if hypokalaemia develops from thiazide use 3
• Ad libitum fluid access to prevent dehydration 3

Critical Safety Monitoring

Hyponatremia Prevention

The major life-threatening complication of desmopressin is hyponatremia, which can cause seizures, coma, respiratory arrest, or death 1, 5:

• Ensure serum sodium is normal before starting or resuming desmopressin 1
• Measure serum sodium within 7 days and at 1 month after initiating therapy, then periodically during treatment 1
• Monitor more frequently in patients ≥65 years and those at increased risk 1
• Initiate fluid restriction during desmopressin treatment 1, 5
• Temporarily or permanently discontinue desmopressin if hyponatremia occurs 1

Contraindications

Desmopressin is contraindicated in patients with:

• Excessive fluid intake 1
• Illnesses causing fluid or electrolyte imbalances 1
• Concurrent use of loop diuretics or systemic/inhaled glucocorticoids 1

Special Populations

Pediatric Patients

• Infants and young children require specialized management with dietitian support for nutritional adequacy 3
• Tube feeding may be necessary in 20-30% of children, typically discontinued by age 4 years 3
• Close monitoring of weight, fluid balance, and biochemistry is crucial when starting treatment due to risk of marked hyponatremia 3

Surgical/Fasting Situations

For patients unable to maintain oral intake (e.g., pre-anesthesia):

• Administer 5% dextrose in water intravenously at maintenance rate 3
• Monitor blood glucose regularly to prevent hyperglycemia-induced osmotic diuresis 3
• Expect urine volume to decrease considerably with IV fluid administration 3

Long-Term Follow-Up

For Central DI

• Regular monitoring of serum electrolytes, urine volume/osmolality, and body weight 4
• Close follow-up for idiopathic central DI as it may be the first manifestation of underlying pathology (tumors, infiltrative disease) 6, 7
• Repeat pituitary MRI if new symptoms develop or disease progression suspected 3

For Nephrogenic DI

• Ultrasound of urinary tract every 2-3 years to detect complications like urinary tract dilatation or bladder dysfunction 3, 4
• Regular assessment of drug treatment efficacy balancing benefits against risks, particularly chronic NSAID use and CKD progression 3
• Monitor for CKD development, as approximately 50% of adults with nephrogenic DI develop CKD stage ≥2 3