What is the drug of choice for treating nocturnal (nighttime) enuresis?

Drug of Choice for Nocturnal Enuresis

Desmopressin is the drug of choice for treating nocturnal enuresis, particularly in children with nocturnal polyuria who have normal bladder capacity. 1, 2

First-Line Treatment Options

Non-Pharmacological Approaches

Before initiating medication, consider these non-pharmacological interventions:

• Enuresis alarm: 66% initial success rate with more than half experiencing long-term success 2
• Lifestyle modifications:
  • Regular voiding schedule during daytime
  • Liberal fluid intake during morning and early afternoon
  • Limited evening fluid intake (200 ml or less after dinner)
  • Avoiding caffeinated beverages before bedtime
  • Treating constipation if present

Pharmacological First-Line: Desmopressin

• Mechanism: Synthetic analogue of antidiuretic hormone (ADH) that decreases nighttime urine production 1
• Efficacy: 30% full response, 40% partial response 1
• Best candidates: Children with nocturnal polyuria (nocturnal urine production >130% of expected bladder capacity) 1
• Dosage:
  • Oral tablets: 0.2-0.4 mg taken 1 hour before bedtime
  • Oral melt formulation: 120-240 μg taken 30-60 minutes before bedtime 1
• Safety considerations:
  • Risk of water intoxication with hyponatremia if combined with excessive fluid intake
  • Limit evening fluid intake to 200 ml or less
  • Oral formulations preferred over nasal spray 1

Second-Line Treatment Options

Anticholinergics

• Consider as add-on therapy for patients with signs of bladder overactivity or reduced capacity 1
• Options include oxybutynin, tolterodine, and propiverine
• Not considered first-line therapy for nocturnal enuresis 1

Tricyclic Antidepressants (Imipramine)

• Efficacy: 40-60% effectiveness, but high relapse rate (50%) 1
• Dosage: 1.0-2.5 mg/kg at bedtime 1, 3
  • For children aged 6 and older: Start with 25 mg/day
  • Can increase to 50 mg nightly in children under 12 years
  • Children over 12 may receive up to 75 mg nightly 3
• Safety concerns:
  • Risk of cardiac arrhythmia
  • Consider pretreatment electrocardiogram 1
  • Risk of serious consequences if ingested by younger siblings 1

Treatment Algorithm

1. Initial evaluation:

   • Urinalysis to rule out underlying conditions
   • Frequency-volume chart documenting fluid intake, voided volumes, and wet/dry nights
   • Assessment of nocturnal urine production

2. Start with non-pharmacological approaches:

   • Lifestyle modifications
   • Enuresis alarm if family is motivated and compliant

3. If non-pharmacological approaches fail or are not feasible:

   • First choice: Desmopressin for children with nocturnal polyuria
   • Monitor response using calendar of wet/dry nights

4. If inadequate response to desmopressin:

   • Consider combination therapy (desmopressin + anticholinergics) if signs of bladder overactivity
   • Consider imipramine as a third-line option, with appropriate cardiac monitoring

5. Regular follow-up:

   • Monthly appointments to sustain motivation and adjust treatment plan
   • For desmopressin, consider regular drug holidays to assess if medication is still needed 1

Important Considerations

• Treatment should not be started before age 6 years 2
• Emphasize that bedwetting is not the fault of the child or parents 1
• Avoid punitive approaches as they can worsen psychological impact 2
• Relapse is common after discontinuation of pharmacological treatment, particularly with imipramine 1
• Combined therapy approaches may be more effective than monotherapy for resistant cases 4

Remember that desmopressin provides immediate anti-enuretic effects and is particularly effective in children with nocturnal polyuria, making it the drug of choice for most cases of nocturnal enuresis 1, 2.