EVIDENCE-BASED ANSWER
For children with primary nocturnal enuresis, treatment with enuresis alarms reduced the number of wet nights by almost 4 per week, with almost half of patients remaining dry for 3 months after treatment (strength of recommendation [SOR]: A, based on a systematic review of homogeneous randomized control trials [RCTs]). Desmopressin (DDAVP) and tricyclic drugs reduce the number of wet nights by 1 to 2 per week during treatment, although the effect is not sustained after treatment is finished (SOR: A, based on a SR of homogeneous RCTs). Dry bed training with an alarm results in an additional reduction of wet nights over alarms alone (SOR: A, based on a systematic review of homogeneous RCTs].
CLINICAL COMMENTARY
Alarms have a high success rate with commitment; desmopressin good for temporary reduction
Nocturnal enuresis is embarrassing to children and frustrating to parents. Even though it has a usually benign, self-limited course, many families want to hear about treatment options. Enuresis alarms have a high success rate in achieving dry nights during treatment and maintaining dry nights once treatment stops. The success of alarms requires a motivated child and family plus a significant time and effort commitment for 3 to 6 months.
Since desmopressin rapidly reduces bedwetting, it is a good choice for situational use such as sleepovers, camping, and holidays. Desmopressin has minimal adverse reactions such as nasal irritation, nausea, and headaches, but parents should minimize evening water intake to prevent rare water intoxication side effects. The lack of benefit of desmopressin and alarm combination therapy may be partly explained by the loss of learning, if desmopressin negates the alarm needing to trigger. Since tricyclic medications do not show a benefit over desmopressin, they should be considered second-line agents due to cardiotoxic side effects and life-threatening overdose outcomes.
Evidence summary
Nocturnal enuresis is an involuntary loss of urine at night in the absence of congenital or acquired central nervous system defect among children over 5 years of age.1-4 Approximately 15% of children aged >5years wet their bed at night.5 The spontaneous resolution rate is about 15% per year.5 Before primary care treatment, indications for urological referral should be excluded, including daytime wetting, abnormal voiding (unusual posturing, discomfort, straining, or poor urine stream), recurrent urinary tract infections, neurological and anatomical anomalies, and urgency symptoms.4
The Cochrane Incontinence Group Trials demonstrated that enuresis alarms led to nearly 4 fewer wet nights per week compared with no treatment or placebo (weighted mean difference [WMD]=–3.65; 95% confidence interval [CI], –4.52 to –2.78).1 The relative risk of failure was 0.36 compared with placebo (95% CI, 0.26 to 0.40). The number needed to treat (NNT) to achieve 14 consecutive dry nights is 2. About half the children relapse after stopping treatment, compared with nearly all children after control interventions (55% vs 99%). Evidence is insufficient to say whether the addition of dry bed training (scheduled awakenings, cleanliness training, social reinforcement, positive practice) improves the outcomes. Alarms that wake the child immediately (vs a time delay) and alarms that wake the child (instead of the parents) were slightly more effective.
A meta-analysis also showed that desmopressin (10-60 μg) at bedtime reduced bedwetting by 1 to 2 nights per week compared with placebo (WMD=1.34; 95% CI, -1.57 to –1.11 with a dose of 20 μg).6 The NNT to achieve 14 consecutive dry nights is 7. However, the data suggest once treatment stops, there is little difference between desmopressin and placebo. Some evidence suggested that a higher dose was more likely to decrease the number of wet nights; however, there was no difference in cure rates. Evidence comparing intranasal with oral administration is insufficient.2
In the Cochrane review, children treated with desmopressin had 1.7 fewer wet nights (WMD=1.7; 95% CI, –2.95 to –0.45) in the first week compared with children treated with alarms.6 However, at the end of 3 months, alarms were associated with 1.4 fewer wet nights per week than children treated with desmopressin (WMD=1.4; 95% CI, 0.14 to 2.66).