What is the recommended dose of desmopressin (DDAVP) for children with nocturnal enuresis and what are the warnings for its use?

From the Guidelines

The recommended dose of desmopressin (DDAVP) for children with nocturnal enuresis is typically 0.2-0.4 mg orally at bedtime, starting with the lowest dose and titrating upward if needed, as suggested by the most recent and highest quality study 1. When using desmopressin, it is essential to consider the following warnings:

• Fluid intake should be restricted from 1 hour before until 8 hours after administration to prevent hyponatremia, which is the most serious potential side effect.
• The medication should be temporarily discontinued during acute illnesses that might affect fluid balance, such as fever, vomiting, or diarrhea.
• Desmopressin works by mimicking the action of antidiuretic hormone (vasopressin), reducing urine production overnight by increasing water reabsorption in the kidneys.
• This medication is not recommended for children under 5 years of age, and treatment should include periodic breaks to assess if continued therapy is necessary.
• Parents should monitor for symptoms of hyponatremia including headache, nausea, vomiting, decreased appetite, muscle weakness, confusion, and unusual tiredness, which require immediate medical attention. Some key points to consider when using desmopressin for nocturnal enuresis include:
• The ordinary dose of the tablets is 0.2 to 0.4 mg and this dose is not influenced by body weight or age 1.
• The antidiuretic activity of desmopressin can be suspected to be a cause of its beneficial effect in enuresis cases and indeed nocturnal polyuria is a positive predictor of the therapeutic response 1.
• Desmopressin is most efficient in children with nocturnal polyuria and normal bladder reservoir function 1.
• If combined with an excessive fluid intake, desmopressin can cause water intoxication with hyponatremia and convulsions, thus oral formulations are preferred and polydipsia is a contraindication to desmopressin treatment 1.

From the Research

Dosis for Desmopressin in Children for Enuresis

• The recommended dose of desmopressin for children with nocturnal enuresis is between 0.2 mg to 0.6 mg, administered orally at bedtime 2.
• A study found that 44% of desmopressin-treated patients achieved at least a 50% reduction from baseline in the number of wet nights per 2 weeks at the lower doses of 0.2 and 0.4 mg 2.
• Another study suggested that desmopressin is effective in reducing bedwetting in a variety of doses and forms, with each dose reducing bedwetting by at least one night per week during treatment compared to placebo 3.

Warnings for the Use of Desmopressin

• Desmopressin can cause water intoxication and severe hyponatremia if given without adequate restriction of water intake 3, 4.
• Children should be advised not to drink more than 240 ml (8 oz) fluid during desmopressin treatment to avoid the possible risk of water intoxication 3.
• The use of desmopressin was generally considered safe, but additional measures should be taken to prevent severe hyponatremia, such as periodic measurement of serum sodium levels 5, 4.

Special Considerations

• A sex difference in renal sensitivity to desmopressin has been reported, with girls being more sensitive than boys 6.
• The pharmacokinetics and pharmacodynamics of desmopressin in children are not well established, and further studies are needed to determine the optimal dosing regimen and to fill in the knowledge gaps in pediatric pharmacological aspects of desmopressin 5.