What is the recommended treatment for bedwetting using Desmopressin (DDAVP)?

Desmopressin for Bedwetting: Treatment Recommendations

Desmopressin is an evidence-based first-line pharmacological treatment for bedwetting that reduces wet nights by approximately 30-40% during active treatment, with oral formulations strongly preferred over nasal spray due to safety concerns. 1

Optimal Candidates for Desmopressin

Desmopressin works best in children with nocturnal polyuria (nighttime urine production >130% of expected bladder capacity for age) and normal bladder function (maximum voided volume >70% of expected bladder capacity). 1

Other appropriate candidates include: 1

• Children in whom alarm therapy has failed
• Children unlikely to comply with alarm therapy
• Situations requiring immediate effect (sleepovers, camps)

Dosing and Administration

Oral Tablets

• Dose: 0.2-0.4 mg taken at least 1 hour before sleep 1, 2
• Maximum renal concentrating effect occurs 1-2 hours after administration 1
• Dose is not influenced by body weight or age 1

Oral Melt Tablets (Lyophilisate)

• Dose: 120-240 mcg taken 30-60 minutes before bedtime 1, 2
• Not yet available in all countries 1

Dosing Strategy

You may either: 1

• Start with the higher dose and taper down if effective, OR
• Start low and titrate up if needed
• The anti-enuretic effect is seen immediately 1

Critical Safety Requirements

MANDATORY FLUID RESTRICTION: Evening fluid intake must be limited to 200 ml (6 ounces) or less, with no drinking until morning. 1, 2, 3

Contraindications and Warnings

• Polydipsia (excessive thirst/drinking) is an absolute contraindication 1, 2, 3
• Nasal spray formulations are strongly discouraged due to higher risk of water intoxication with hyponatremia and convulsions 1, 2, 3
• The enuresis indication has been removed for nasal spray in many countries 1, 3

Mechanism of Serious Adverse Event

Desmopressin combined with excessive fluid intake can cause water intoxication leading to hyponatremia and seizures. 1, 2

Treatment Duration and Monitoring

Daily Use Strategy

• If using desmopressin daily, schedule regular short drug holidays to assess whether medication is still needed 1, 2, 3
• The effect is immediate, so families can quickly determine ongoing necessity 1

Intermittent Use Strategy

• Families may choose to use desmopressin only before "important nights" (sleepovers, travel) rather than daily 1
• This approach is equally valid and avoids concerns about long-term use 1

Expected Outcomes

During Treatment

• Approximately 30% of children become full responders (completely dry) 1
• 40% achieve partial response (significant reduction in wet nights) 1
• Each dose reduces bedwetting by at least one night per week compared to placebo 4

After Treatment Stops

• The curative potential is low - most children relapse after discontinuation 1
• This contrasts with alarm therapy, which has better sustained benefits after treatment ends 4

Comparison with Alternative Treatments

Alarm Therapy

• Alarms may produce more sustained long-term benefits than desmopressin 4
• Success rate approximately 66% with better outcomes after treatment stops 2
• One trial showed alarms resulted in fewer failures/relapses (RR 9.17) compared to desmopressin 4

Combination Therapy

• Alarm treatment supplemented with desmopressin resulted in fewer wet nights during treatment (WMD -1.35) compared to alarms alone 4
• However, data are inconclusive about whether this improves long-term cure rates 4

When Desmopressin Fails

Anticholinergic Addition

If standard desmopressin treatment fails and there is evidence of detrusor overactivity: 1

• Consider adding anticholinergics (tolterodine 2 mg, oxybutynin 5 mg, or propiverine 0.4 mg/kg at bedtime)
• Approximately 40% of treatment-resistant children respond to this combination 1
• Must first exclude constipation, post-void residual urine, and ensure regular voiding habits 1

Important Prerequisites Before Anticholinergics

• Complete frequency-volume chart 1
• Uroflowmetry with ultrasound measurement of post-void residual urine 1
• Treat any constipation present 1

Essential Baseline Measures

Before starting desmopressin: 1

• Urine dipstick (mandatory) - rule out glycosuria and proteinuria
• Frequency-volume chart for at least 2 days to document nocturnal polyuria
• Consider weighing diapers to assess nocturnal urine production

Common Pitfalls to Avoid

1. Using nasal spray formulation - significantly higher risk of hyponatremia 1, 2, 3
2. Inadequate fluid restriction counseling - families must understand the 200 ml limit 1, 2, 3
3. Continuing indefinitely without drug holidays - prevents assessment of ongoing need 1, 2, 3
4. Expecting cure rather than symptom control - set realistic expectations about relapse after stopping 1, 4
5. Not screening for polydipsia - this is an absolute contraindication 1, 2, 3

Overall Safety Profile

Desmopressin is generally safe with few side effects when used correctly for several years. 1 The single critical safety concern is water intoxication, which is entirely preventable with proper fluid restriction. 1, 2