What are the guidelines for using desmopressin (DDAVP) in treating diabetes insipidus and nocturnal enuresis?

Guidelines for Using Desmopressin (DDAVP) in Diabetes Insipidus and Nocturnal Enuresis

Desmopressin is the first-line treatment for central diabetes insipidus and an effective option for nocturnal enuresis, with oral formulations preferred over nasal spray due to safety concerns regarding hyponatremia risk. 1, 2

Indications

• Desmopressin is indicated for:

  • Central diabetes insipidus - as antidiuretic replacement therapy 2
  • Management of temporary polyuria and polydipsia following head trauma or pituitary surgery 2
  • Nocturnal enuresis, particularly in children with nocturnal polyuria 3

• Desmopressin is NOT indicated for:

  • Nephrogenic diabetes insipidus (ineffective) 2
  • Patients with polydipsia (contraindicated) 2

Dosing Guidelines

For Central Diabetes Insipidus:

• Daily dose: 2-4 mcg administered as one or two divided doses by subcutaneous or intravenous injection 2
• Dosage must be individualized according to patient response 2, 4
• Oral formulations are available with different dosing requirements 2

For Nocturnal Enuresis:

• Oral tablets: 0.2-0.4 mg taken at least 1 hour before bedtime 3
• Oral melt tablets: 120-240 mcg taken 30-60 minutes before bedtime 3
• Dose is not influenced by body weight or age in children 3

Patient Selection

For Nocturnal Enuresis:

• Most effective in children with:
  • Nocturnal polyuria (urine production >130% of expected bladder capacity) 3
  • Normal bladder reservoir function (maximum voided volume >70% of expected bladder capacity) 3
• Also suitable for patients in whom alarm therapy has failed or those unlikely to comply with alarm therapy 3

Safety Considerations

Hyponatremia Risk:

• Most significant safety concern is water intoxication with hyponatremia and potential convulsions 3, 2
• Risk factors include:
  • Excessive fluid intake 2
  • Use of nasal spray formulations 3, 1
  • Concomitant use of medications that can cause fluid/electrolyte imbalances 2
  • Extremes of age 5, 6

Contraindications:

• Known hypersensitivity to desmopressin 2
• Moderate to severe renal impairment (creatinine clearance <50 mL/min) 2
• Hyponatremia or history of hyponatremia 2
• Syndrome of inappropriate antidiuretic hormone secretion 2
• Polydipsia 2
• Concomitant use with loop diuretics or systemic/inhaled glucocorticoids 2
• Illnesses causing fluid or electrolyte imbalances 2
• Heart failure or uncontrolled hypertension 2

Administration Guidelines

Fluid Restriction:

• Evening fluid intake should be limited to 200 mL (6 ounces) or less 3, 1
• No drinking until morning 3
• This restriction is crucial to prevent water intoxication 3, 1

Formulation Preferences:

• Oral formulations (tablets or melt tablets) are preferred over nasal spray 3, 1
• Nasal spray has been associated with higher risk of hyponatremia and has had the enuresis indication removed in many countries 3, 1

Monitoring

• Ensure normal serum sodium concentration before starting treatment 2
• Measure serum sodium within 1 week and approximately 1 month after starting therapy 2
• Monitor serum sodium periodically during treatment, more frequently in:
  • Patients ≥65 years of age 2
  • Patients at increased risk of hyponatremia 2
• For long-term use, implement regular short drug holidays to assess whether medication is still needed 3, 1

Treatment Response

• Antidiuretic effect is seen immediately 3
• For nocturnal enuresis, families can choose between daily medication or administration before important nights only 3
• Overall, desmopressin is effective in approximately 30% of children with enuresis as full responders and 40% with partial response 3
• The curative potential for nocturnal enuresis is low 3

Practical Considerations

• Keep a calendar of dry and wet nights to establish baseline and monitor treatment effect 3
• Regular voiding habits should be maintained during the day, especially at bedtime and upon awakening 3
• If constipation is present, it should be treated to optimize response 3

By following these guidelines, desmopressin can be used effectively and safely for the management of central diabetes insipidus and nocturnal enuresis, with appropriate monitoring to minimize the risk of hyponatremia.